Acta Agronomica Sinica

Table of Content

12 April 2023, Volume 49 Issue 4

Previous Issue Next Issue

REVIEW

Research advance on annual water use efficiency of winter wheat-summer maize cropping system in North China Plain

ZHANG Jin-Xin, GE Jun-Zhu, MA Wei, DING Zai-Song, WANG Xin-Bing, LI Cong-Feng, ZHOU Bao-Yuan, ZHAO Ming

Acta Agronomica Sinica. 2023, 49(4): 879-892. doi:10.3724/SP.J.1006.2023.21034

Abstract ( 654 )

HTML ( 48 )

PDF (931KB) ( 989 )

Save

Figures and Tables | References | Related Articles | Metrics

Improving water use efficiency without reducing the annual grain yield is the key to promoting the sustainable development of the winter wheat-summer maize cropping system in the North China Plain. Since the middle and late 20th century, many researches have explored ways to improve the annual water use efficiency of winter wheat-summer maize, including development of water-saving irrigation technology, optimizing of irrigation system, establishment of alternative water-saving cropping system, and breeding new variety of water-saving and drought resistant, which significantly improved the crop water use efficiency (WUE). Here, we summarized the research advance on efficient annual water utilization of winter wheat-summer maize cropping system in North China Plain, and proposed a way regulating the annual water balance through using appropriate tillage or sowing/harvest date to improve water use efficiency of winter wheat-summer maize cropping system. It could provide theory and technical support for the establishment of water-saving and high-yield cultivation cropping system of winter wheat-summer maize in the North China Plain.

CROP GENETICS & BREEDING · GERMPLASM RESOURCES · MOLECULAR GENETICS

BnABCI8 affects chloroplast development of Brassica napus

CHEN Xiao-Han, WANG Li-Qin, WANG Hua-Dong, XIAO Qing, TAO Bao-Long, ZHAO Lun, WEN Jing, YI Bin, TU Jin-Xing, FU Ting-Dong, SHEN Jin-Xiong

Acta Agronomica Sinica. 2023, 49(4): 893-905. doi:10.3724/SP.J.1006.2023.24065

Abstract ( 408 )

HTML ( 74 )

PDF (10158KB) ( 253 )

Save

Figures and Tables | References | Related Articles | Metrics

Mature chloroplast is an important place for photosynthesis of higher plants and important organs that affects crop yield. BnABCI8 is a member of the ABC transporter I subfamily, and there are two functional copies of BnA09.ABCI8 and BnC09.ABCI8 in Brassica napus. Their amino acid sequences are very conserved in different species. The relative expression patterns showed that BnABCI8 was expressed in all tissues of Brassica napus, and the relative expression level in leaves and flowers was higher. Subcellular localization indicated that BnABCI8 was located in chloroplast. Phenotypic identification showed that the double mutation of BnA09.ABCI8 and BnC09.ABCI8 and the single mutation of BnA09.ABCI8 both resulted in yellow cotyledons and chlorotic true leaves, among which double mutant was more severe chlorosis. Transmission electron microscope demonstrated that the chloroplasts in the double mutants could not form normal thylakoid membranes. The knock-out of BnABCI8 resulted in the decrease of the relative expression level of related genes in the chlorophyll synthesis pathway, and significantly increased the iron content in mutant leaves. These results indicated that the mutation of BnABCI8 resulted in abnormal chloroplast structure, hindered the synthesis of chlorophyll, and significantly increased the iron content in the leaves. In addition, the accumulation of iron ion might lead to a series of reactions such as accumulation of reactive oxygen species, cell death and chlorophyll degradation, and eventually led to mutation of leaf color.

CROP GENETICS & BREEDING · GERMPLASM RESOURCES · MOLECULAR GENETICS

Transcription factor TaMYB5-3B is associated with plant height and 1000- grain weight in wheat

ZHU Zhi, LI Long, LI Chao-Nan, MAO Xin-Guo, HAO Chen-Yang, ZHU Ting, WANG Jing-Yi, CHANG Jian-Zhong, JING Rui-Lian

Acta Agronomica Sinica. 2023, 49(4): 906-916. doi:10.3724/SP.J.1006.2023.21029

Abstract ( 468 )

HTML ( 43 )

PDF (1500KB) ( 397 )

Save

Figures and Tables | References | Related Articles | Metrics

MYB transcription factor plays an important role in plant growth and development. In this study, we cloned TaMYB5-3B gene on chromosome 3B in wheat. The full-length genome sequence is 3005 bp, including 2112 bp promoter region and 893 bp coding region. TaMYB5-3B coding region consists of two exons and one intron, which encodes a R2R3-MYB protein. The polymorphism of TaMYB5-3B was analyzed by sequencing 32 wheat accessions with wide variations. A total of eight SNPs were detected at -2048, -1632, -1178, -1156, -504, -461, -433, and 61 bp, respectively. They were eight SNPs linked by G/A conversion, G/A conversion, G/A conversion, T/C conversion, C/T conversion, A deletion, T deletion and T/A inversion, respectively. A pair of molecular markers were developed based on the promoter region SNP-1632 to detect the genotypes of wheat natural population. The association analysis of genotype and phenotypic traits showed that TaMYB5-3B was significantly associated with plant height (PH), peduncle length (PLE), and 1000-grain weight (TGW). Two haplotypes (Hap-3B-1 and Hap-3B-2) were detected in the population, in which Hap-3B-2 was an excellent haplotype with short PH and high TGW. Hap-3B-2 had been positively selected in the breeding, and its frequency in modern cultivars gradually increased with the advance of breeding years in China. Therefore, TaMYB5-3B could be used to further understand the mechanism of wheat plant height and grain yield formation, and its molecular markers may contribute to ideal plant architecture and grain yield breeding of wheat.

Identification of SUMO protein family members and functional study of Bna.SUMO1.C08 gene in Brassica napus

CHEN Hui, XIAO Qin, WANG Hua-Dong, WEN Jing, MA Chao-Zhi, TU Jin-Xing, SHEN Jin-Xiong, FU Ting-Dong, YI Bin

Acta Agronomica Sinica. 2023, 49(4): 917-925. doi:10.3724/SP.J.1006.2023.24064

Abstract ( 375 )

HTML ( 29 )

PDF (5922KB) ( 228 )

Save

Figures and Tables | References | Related Articles | Metrics

Post-translational modifications are very important for protein function. SUMOylation is a very important post-translational modification, which has great influence on the key processes of plant growth and development. As an important oil and economic crops, there is few studies on SUMO modification in Brassica napus. To remedy this gap, SUMOylation in Brassica napus was investigated in this study. Firstly, 31 SUMO proteins were identified in Brassica napus by bioinformatics methods, which were divided into three groups (“canonical” SUMO, “non-canonical” SUMO, and SUMO-V). Secondly, the relative expression pattern indicated that, Bna.SUMO1.C08, a homologous gene of AtSUMO1, was highly expressed in roots, leaves, and silique. Subcellular localization revealed that Bna.SUMO1.C08 was localized in the nucleus and endoplasmic reticulum. Finally, Bna.SUMO1.C08 was overexpressed in Brassica napus and Bna.SUMO1.C08 could enhance plant resistance to PEG stress. This study laid a foundation for the subsequent research on SUMO modification in Brassica napus.

Genotypes screening and comprehensive evaluation of sweetpotato tolerant to low potassium stress at seedling stage

LIU Ming, FAN Wen-Jing, ZHAO Peng, JIN Rong, ZHANG Qiang-Qiang, ZHU Xiao-Ya, WANG Jing, LI Qiang

Acta Agronomica Sinica. 2023, 49(4): 926-937. doi:10.3724/SP.J.1006.2023.24080

Abstract ( 433 )

HTML ( 29 )

PDF (517KB) ( 666 )

Save

Figures and Tables | References | Related Articles | Metrics

The purpose of this study was to establish a low potassium (K) tolerant evaluation system for sweetpotato at seedling stage and to screen sweetpotato materials with low-K-tolerant and low-K-sensitive. 214 sweetpotato varieties (lines) from domestic and abroad were cultured under low-K-stress (0 mmol L^-1 K₂O, LK) and normal K treatment (10 mmol L^-1 K₂O, CK) through a hydroponic experiment. 11 traits, such as biomass, K accumulation, K content, and K utilization efficiency were collected to calculate the low-K-stress tolerance index of each index. The low-K-tolerant ability of each sweetpotato material was comprehensively evaluated by principal component analysis (PCA), regression analysis, and cluster analysis. The results showed that the biomass and K uptake and utilization characteristics of different sweetpotato materials were different under two K levels. Under LK treatment, shoot biomass (SB), shoot biomass increase (SBI), root biomass increase (RBI), total biomass increase (PBI), K accumulation in shoot (KAS), K accumulation in root (KAR), K accumulation in plant (KAP), K concentration in shoot (KCS), and K concentration in root (KCR) decreased by more than 29% compared with CK, while root shoot ratio (RSR) and K physiological utilization efficiency (KUE) increased by 29.63% and 120.56%, respectively. Under LK treatment, the variation coefficients of SB, SBI, PBI, KAS, KAP, KCS, KCR, and KUE of different sweetpotato materials were higher than those of CK treatment. Principal component analysis was carried out on the low-K-stress tolerant index of 11 indexes. Three principal components (PC) were selected and the cumulative variance contribution rate was 82.86%. The low-K-tolerant index of 11 indicators was significantly correlated with the comprehensive evaluation value (Y) of low-K-tolerant. Selected SBI, RBI, PBI, KAS, KAR, KAP as screening evaluation indicators, 214 sweetpotato materials were divided into low-K-tolerant type, intermediate type and low-K-sensitive type according to cluster heat map analysis. The variance analysis showed that the low-K-tolerant varieties had higher low-K-stress tolerance index than other types of varieties, and the Y-value was also in the top, which verified the accuracy of the clustering results. Based on the results of this study, SBI, RBI, PBI, KAS, KAR, and KAP can be used as the first selection indexes for the screening of sweetpotato with different low-K-tolerance ability at seedling stage. Six genotypes with the strongest tolerance to low K at seedling stage were selected, which were Jizishu 18, Guangzishu 2, Longshu 710, Taizhong 6, Shenglibaihao, and Longshu 9.

Genome-wide identification and expression analysis of SWEET genes from peanut genomes

SUN Quan-Xi, YUAN Cui-Ling, MOU Yi-Fei, YAN Cai-Xia, ZHAO Xiao-Bo, WANG Juan, WANG Qi, SUN Hui, LI Chun-Juan, SHAN Shi-Hua

Acta Agronomica Sinica. 2023, 49(4): 938-954. doi:10.3724/SP.J.1006.2023.24066

Abstract ( 627 )

HTML ( 54 )

PDF (5306KB) ( 250 )

Save

Figures and Tables | References | Related Articles | Metrics

SWEET (sugars will eventually be exported transporter) proteins are structurally conserved and energy independent sugar transporters, which play important roles in many physiological processes, such as plant growth development and response to biotic and abiotic stresses. At present, there is no research study about SWEET gene in peanut yet. In this study, we explored SWEET gene in the whole genome of peanut for the first time and analyzed its molecular characteristics and expression pattern in detail. These results showed that there were 55, 25, and 28 SWEET genes in the genomes of cultivated peanut and two ancestral wild peanuts, respectively, which were randomly and unevenly distributed on each chromosome. Orthologous genes from wild peanut and cultivated peanut usually shared the similar chromosome location, which confirmed that cultivated peanut originated from two ancestral wild peanuts. There were also some orthologous gene lost, which might be attributed to gene deletion or expansion during genome replication and doubling process. Gene structure and cis-elements in the promoter region were different in the SWEET genes, suggesting the diversity of biological functions. Phylogenetic analysis divided Arachis SWEET proteins into four subfamilies Clade I-Clade IV. Genes in the same clade of the same subfamily exhibited the similar gene structure. Based on Clevenger et al. tissue expression analysis, we found that some genes were tissue preferentially expressed, which provided a reference for further understanding the functional location of SWEET genes. Moreover, we identified several drought or salt stress responsive genes, such as AhSWEET3a and AhSWEET4e by re-analysis transcriptome expression data under abiotic stress and RT-qPCR. Their functions were still needed to be further identified. These results provide a theoretical reference for further analysis of SWEET gene function in peanut.

Expression pattern analysis and interaction protein screening of cassava MYB transcription factor MeMYB60

XU Zi-Yin, YU Xiao-Ling, ZOU Liang-Ping, ZHAO Ping-Juan, LI Wen-Bin, GENG Meng-Ting, RUAN Meng-Bin

Acta Agronomica Sinica. 2023, 49(4): 955-965. doi:10.3724/SP.J.1006.2023.24089

Abstract ( 530 )

HTML ( 26 )

PDF (5997KB) ( 690 )

Save

Figures and Tables | References | Related Articles | Metrics

Myeloblastosis (MYB) transcription factors widely involve in a variety of physiological and biochemical processes in plants, and play important regulatory roles in response to abiotic stress in plant. Based on the expression pattern of MYB members in cassava cultivars, an R2R3-MYB transcription factor, namely MeMYB60 was screened and cloned. Gene expression characteristics showed that MeMYB60 was specifically expressed in leaves of cassava, and negatively regulated by drought stress and low temperature. Moreover, this gene was also responded to ABA treatment in leaves of cassava. Promoter activity analysis showed that MeMYB60 could be expressed in guard cells, indicating that the expression of this transcription factor gene may be related to stomatal movement regulation in cassava. MeMYB60 protein was predominately located in the nucleus and had transcriptional activation activity. Its transcriptional activation domain was in the range of 194th-343rd amino acid residues at the C-terminal of the protein. The cDNA library of drought stressed cassava leaves was screened by using the 1st-194th amino acid residues at the N-terminal of MeMYB60 protein as bait. Subsequently, 18 proteins had been that may interact with MeMYB60. Yeast-two-hybrid analysis determined that MeCatlase1 and MeCataase2 are potential interactors of MeMYB60, respectively. These results lay a foundation for further functional study of MeMYB60 in cassava in response to abiotic stress and are helpful for the regulatory network investigation of MeMYB60.

Screening of active LTR retrotransposons in wheat (Triticum aestivum L.) seedlings and analysis of their responses to abiotic stresses

ZHOU Bin-Han, YANG Zhu, WANG Shu-Ping, FANG Zheng-Wu, HU Zan-Min, XU Zhao-Shi, ZHANG Ying-Xin

Acta Agronomica Sinica. 2023, 49(4): 966-977. doi:10.3724/SP.J.1006.2023.21023

Abstract ( 418 )

HTML ( 16 )

PDF (14488KB) ( 143 )

Save

Figures and Tables | References | Related Articles | Metrics

LTR (long terminal repeat) retrotransposable elements account for more than 60% of rye genome. It is of great significance to screen active LTR retrotransposons from wheat genome and analyze their transposition, the relative expression levels, and methylation levels under abiotic stress in exploring the role of retrotransposable elements in improving wheat anti-stress ability. Four active LTR retrotransposons (Fatima, Wis, Angela, and Babara) with complete structure were selected from the TREP database by bioinformatics analysis. The relative expression levels, methylation dynamics, and transposition activity of the four LTR retrotransposons were then analyzed at seedling stage (two leaves with one heart) leaves and roots of the stress-treated (NaCl, ABA, H₂O₂, and PEG) wheat seedlings by qRT-PCR, methylation-specific polymerase chain reaction (MSP), and transposon display method. The results suggested that the four retrotransposons had basic transcription activity under normal conditions, which could be changed under stress conditions, and their variation tendency was similar in the same stress conditions. The up-regulation of Fatima, Angela, and Babara was due to their down-regulated methylation levels, while Wis was opposite. The 3′LTR of LTR retrotransposons contained many stress-responsive cis-elements, but the regulatory effect of which were not obvious under stress treatments. Compared with that in leaves, the four LTR retrotransposons in roots were more sensitive to stresses and had higher transposition activity. This study will help to further reveal the response regularity of LTR retrotransposons under stress conditions and accumulate data for improving of stress resistance breeding wheat by using transposable elements.

Study on VIGE system mediated by different plant viruses in cotton

LEI Jian-Feng, LI Yue, DAI Pei-Hong, ZHAO Yi, YOU Yang-Zi, JIA Jian-Guo, ZHAO Shuai, QU Yan-Ying, LIU Xiao-Dong

Acta Agronomica Sinica. 2023, 49(4): 978-987. doi:10.3724/SP.J.1006.2023.24071

Abstract ( 516 )

HTML ( 18 )

PDF (5331KB) ( 191 )

Save

Figures and Tables | References | Related Articles | Metrics

Plant virus-mediated sgRNA delivery and expression has tremendous advantage over traditional transformation of intact editing vectors for gene editing, because sgRNA expression can be rapidly amplified and be accumulated along with virus replication and movement, resulting in efficient gene editing efficiency. In this study, to develop and apply more plant virus-mediated gene editing (VIGE) systems in cotton, the overexpressing Cas9 (Cas9-OE) cotton was used as VIGE receptor and the cotton leaf crumple virus (CLCrV) and tobacco rattle virus (TRV) mediated VIGE systems were established in cotton. First of all, both CLCrV and TRV-mediated VIGE could target and knock out the GhBsrk1 and GhMAPKKK2 in subgroup A and subgroup D genomic sequences, which verified the feasibility and effectiveness of these two systems. Further quantificaiton of the editing efficiency of GhBsrk1 and GhMAPKKK2 genes by these two systems showed that both CLCrV and TRV-mediated VIGE could produce high-efficiency gene editing efficiency, and there was no significant difference in gene editing efficiency between the two systems. This study also explored the effect of sgRNAs driven by cotton endogenous U6 promoter and Arabidopsis U6 promoter on VIGE gene editing efficiency. The results showed that both promoter-mediated VIGE were able to produce high-efficiency gene editing efficiency, and there was no significant difference in gene editing efficiency based on these two promoter-mediated VIGE systems. The above results indicate that more plant virus vectors can be developed for the application of cotton gene editing research, thus obtaining an efficient sgRNA screening system.

Effects of overexpression of LrAN2 gene on contents of anthocyanins and glycoalkaloids in potato

LI Hong-Yan, LI Jie-Ya, LI Xiang, YE Guang-Ji, ZHOU Yun, WANG Jian

Acta Agronomica Sinica. 2023, 49(4): 988-995. doi:10.3724/SP.J.1006.2023.24082

Abstract ( 317 )

HTML ( 12 )

PDF (1281KB) ( 608 )

Save

Figures and Tables | References | Related Articles | Metrics

At present, the research on the anthocyanins involved in the MYB gene in potato (Solanum tuberosum L.) is relatively in-depth, but the change rule and regulatory mechanism of the glycoalkaloids (steroidal glycoalkaloids, SGAs) in different tissues, which affect the quality and safety of potato, are still unclear. LrAN2, the MYB gene in Lycium ruthenicum, is associated with the accumulation of anthocyanins in Lycium ruthenicum fruit. In this study, to detect the contents of anthocyanins and SGAs in different tissues, and to analyze the expression of genes related to SGA biosynthesis, wild-type Atlantic and two trans-LrAN2 Atlantic lines (LrAN2oe#66 and LrAN2oe#200) were used as the test materials. The detection of anthocyanins by pH differential method showed that only a certain number of anthocyanins (12 mg 100 g^-1 FW) were detected in the leaves of transgenic plants (LrAN2oe#200). The contents of SGAs by HPLC-TMS in different tissues of the three materials were as follows: leaves>potato skin>potato flesh. There was no significant difference in the contents of SGAs in potato peels. Compared with the control, the SGAs content of LrAN2oe#66 in potato flesh was lower than the control, and the SGAs content of LrAN2oe#200 was significantly increased by 1.3 times, but did not exceed the safety standard (0.2 mg g^-1 FW). The contents of SGAs in LrAN2oe#66 of leaves were increased by 1 times and LrAN2oe#200 was significantly increased by 3.8 times compared with the control. StHMG1 and StSGT2 genes were significantly up-regulated in transgenic plants under the regulation of LrAN2 gene by qRT-PCR. These results give a guiding significance for the accumulation of anthocyanins in potato plants and provide a theoretical basis for further analysis of the regulation mechanism of anthocyanins and SGAs in potato resources.

StEFR1 regulates late blight resistance positively in potato (Solanum tuberosum)

ZHANG Wei-Na, YU Hui-Fang, AN Zhen, LIU Wen-Kai, KANG Yi-Chen, SHI Ming-Fu, YANG Xin-Yu, ZHANG Ru-Yang, WANG Yong, QIN Shu-Hao

Acta Agronomica Sinica. 2023, 49(4): 996-1005. doi:10.3724/SP.J.1006.2023.24062

Abstract ( 313 )

HTML ( 9 )

PDF (4198KB) ( 123 )

Save

Figures and Tables | References | Related Articles | Metrics

Potato late blight is a devastating oomycete disease, which causes great economic losses to agricultural production. In this study, we analyzed the role and potential regulatory mechanism of StEFR1 in regulating late blight resistance by the relative expression pattern and functional verification combined with the bioinformatics methods. Evolutionary analysis showed that the sequence similarity between StEFR1 and AtEFR was 53.9%. After inoculated with Phytophthora infestans for 3 days and treatment with elf18 for 3 hours, the relative expression level of StEFR1 in isolated leaves of Atlantic was upregulated to 1.87 times and 2.31 times compared with the control, respectively. The late blight resistance significantly increased after the overexpression of StEFR1 in the isolated leaves of Atlantic by agrobacterium infiltration method. Compared with the control, the area of leaf lesion size decreased and the activity of leaf cells increased. And the marker genes of PTI, SA, and JA signaling pathways in overexpressed leaves were significantly up-regulated to varied degrees, while the relative expression levels of ET related-genes did not change significantly. In conclusion, StEFR1 was involved in the PTI resistance and regulated the relative expression levels of SA and JA hormone signaling related genes, suggesting that StEFR1 positively regulated the potato late blight. This study lays a foundation for further revealing the molecular mechanism of StEFR1 in regulating the immune response and provides important reference for the molecular breeding of late blight.

Fine mapping of flower colour gene in pea (Pisum sativum L.) based on BSA-seq technique

YAN Xin, XIANG Chao, LIU Rong, LI Guan, LI Meng-Wei, LI Zheng-Li, ZONG Xu-Xiao, YANG Tao

Acta Agronomica Sinica. 2023, 49(4): 1006-1015. doi:10.3724/SP.J.1006.2023.24055

Abstract ( 572 )

HTML ( 46 )

PDF (3876KB) ( 411 )

Save

Figures and Tables | References | Related Articles | Metrics

In recent years, BSA-seq technology has been widely used in the mining of new genes related to agronomic traits. With the development of the first reference genome of pea, it is imperative to combine BSA-seq method with genome-wide sequencing for gene mapping. In this study, we used purple flower parent G0004562, white flower parent G0002930, and F₂ populations for preliminarily locate the target genes controlling flower color by BSA-seq technology, and a mapping region of 31.42 Mb was obtained. Then, the InDel molecular markers were designed to further narrow the mapping interval, and finally the target gene was located in the range of 0.99 Mb with 19 genes. Based on gene annotation, Psat6g060480.1 was considered as the candidate gene that controled the flower color. The results of this study verified the feasibility of gene mapping by BSA-seq technology in pea.

CROP GENETICS & BREEDING · GERMPLASM RESOURCES · MOLECULAR GENETICS

Cloning of genes involved in cuticular very-long-chain alkane synthesis and its interaction with BnCER1-2 in Brassica napus

BAI Cheng-Cheng, YAO Xiao-Yao, WANG Yu-Lu, WANG Sai-Yu, LI Jin-Ying, JIANG You-Wei, JIN Shu-Rong, CHEN Chun-Jie, LIU Yu, WEI Xing-Yue, XU Xin-Fu, LI Jia-Na, NI Yu

Acta Agronomica Sinica. 2023, 49(4): 1016-1027. doi:10.3724/SP.J.1006.2023.24037

Abstract ( 335 )

HTML ( 13 )

PDF (4783KB) ( 157 )

Save

Figures and Tables | References | Related Articles | Metrics

Very-long-chain (VLC) alkanes are the main components of cuticular wax in Brassica napus, which play a key role in preventing non-stomatal water loss. BnCER1-2 is the core enzyme that catalyzes the synthesis of VLC alkanes in B. napus. However, it is unclear whether BnCER1-2 protein regulates VLC alkane synthesis by interacting with other proteins. Four genes potentially involved in VLC alkane synthesis, BnCER3.a10, BnCER3.c02, BnCYTB5B.c09, and BnCER1-L2.a05, were screened previously by the transcriptome in B. napus with differential wax load. In this study, their coding sequences were cloned from B. napus. A typical fatty acid hydroxylase domain and a wax2 C-terminal domain were detected in the predicted BnCER3.a10/c02 and BnCER1-L2.a05 proteins, while cyt_b5 protein family conserved domain was in the predicted BnCYTB5B.c09. Subcellular localization showed that BnCER3.a10/c02, BnCYTB5B.c09, and BnCER1-L2.a05 were all located in the endoplasmic reticulum, which were co-located with BnCER1-2. Bimolecular fluorescence complementary (BiFC) and luciferase complementation assay (LCA) revealed that BnCER3.a10, BnCYTB5B.c09, and BnCER1-L2.a05 interacted with BnCER1-2 protein, while BnCER3.c02 did not interact with BnCER1-2. The RT-qPCR indicated that BnCER3.a10 and BnCYTB5B.c09 were mainly expressed in the stems or leaves of B. napus, and the relative expression was significantly up-regulated under drought stress, which were consistent with the expression pattern of BnCER1-2. The relative expression levels of BnCER3.a10 decreased significantly under NaCl and low temperature stresses. Further, the relative expression level of BnCER3.a10 was significantly down-regulated by MeJA and ACC, while the relative expression level of BnCYTB5B.c09 was up-regulated by ABA. The highest relative expression of BnCER1-L2.a05 was in flowers and the lowest in stems and leaves, and its expression was significantly down-regulated under drought, cold, and NaCl stresses. Further, the relative expression level of BnCER1-L2.a05 was up-regulated by SA, while down-regulated by MeJA. The relative expression levels of BnCER3.a10 and BnCYTB5B.c09 in B. napus with high wax/alkane load were significantly higher than that with low wax/alkane load, while BnCER1-L2.a05 had the opposite change. Comprehensive analysis suggested that BnCER3.a10 and BnCYTB5B.c09 may promote the biosynthesis of VLC alkanes in B. napus by interacting with BnCER1-2, while BnCER1-L2.a05 may negatively regulate the synthesis of VLC alkanes by interacting with BnCER1-2.

TILLAGE & CULTIVATION · PHYSIOLOGY & BIOCHEMISTRY

Relationship between cotton population, maturity, and the efficacy of harvest aids under high-density planting conditions in Central Hebei province, China

MENG Lu, DU Ming-Wei, LI Fang, QI Hai-Kun, LU Zheng-Ying, XU Dong-Yong, LI Cun-Dong, ZHANG Ming-Cai, TIAN Xiao-Li, LI Zhao-Hu

Acta Agronomica Sinica. 2023, 49(4): 1028-1038. doi:10.3724/SP.J.1006.2023.24104

Abstract ( 338 )

HTML ( 11 )

PDF (456KB) ( 177 )

Save

Figures and Tables | References | Related Articles | Metrics

Chemical defoliation and ripening is the premise of mechanical harvesting of cotton. The population size and maturity of cotton before defoliants significantly affect the efficacy of harvest aids. This field experiment was carried out in Hejian, Hebei in 2016 and 2017. Different varieties (CRI 60, Xinkang 4), planting densities (90,000 plants hm^-2 and 120,000 plants hm^-2), and sowing dates (April 20 and May 10) were used to create different populations. Then, 50% thidiazuron·ethephon suspension agent (T·E) was applied for defoliation and boll opening in late-September. The results showed that there were no differences in leaf number, boll opening percent and ratio of leaf to boll just prior to the application of T·E between two varieties, and 120,000 plants hm^-2 had more leaves and lower percent of open bolls before T·E application compared with 90,000 plants hm^-2. In addition, the late planting produced more leaves and higher ratio of leaf to boll, but lower percent of open bolls than early planting before T·E application. T·E enhanced leaf dropping powerfully, the defoliation was more than 90% at 21 days after T·E application in both years, and the defoliation efficacy was near or beyond 90%, while the number of residual leaves were 8.1-23.3 per square meter. The defoliation did not differ between varieties, plant densities, and sowing dates. However, the 120,000 plants hm^-2 and late planting had more remained leaves than 90,000 plants hm^-2 and early planting in 2017, respectively. In contrast to the excellent defoliation efficacy after T·E application, the efficacy of boll opening of T·E was less than 25%. At 21 days after T·E application, the percentage of open bolls was still lower than 70% in both years. Different varieties and plant densities had similar percent of boll opening, but the late sowing showed lower percent than early sowing. The Spearman partial correlation analysis showed that defoliation, defoliation efficacy and the number of remaining leaves at 7, 14, and 21 days after the T·E treatment were not related to the number of leaves, boll opening rate, and ratio of leaves to bolls before T·E application. However, there was a significant negative correlation between the percent of open bolls at 7, 14, and 21 days after T·E with the number of leaves before T·E (r = -0.393 to -0.432), and a significant positive correlation with the boll opening percent before T·E (r = 0.558 to 0.862). The efficacy of boll opening was also positively correlated with the boll opening percent before T·E. In conclusion, the efficacy of chemical defoliation under high-density population (90,000-120,000 plants hm^-2) in the Yellow River Basin was better, and had a minor relationship with cotton population and maturity before treatment. However, the efficacy of boll opening was low, and the percent of boll opening at 21 days after T·E treatment was less than 95% for mechanical harvesting. In addition, the percent and efficacy of boll opening had a strong dependence on cotton population size and maturity before T·E application. The key to improve the efficacy of harvest aids in cotton is to control the population size and promote earliness through reasonable decision of sowing time and density.

TILLAGE & CULTIVATION · PHYSIOLOGY & BIOCHEMISTRY

Root morphology and physiological characteristics for high yield formation under side-deep fertilization in rice

ZHANG Chen-Hui, ZHANG Yan, LI Guo-Hui, YANG Zi-Jun, ZHA Ying-Ying, ZHOU Chi-Yan, XU Ke, HUO Zhong-Yang, DAI Qi-Gen, GUO Bao-Wei

Acta Agronomica Sinica. 2023, 49(4): 1039-1051. doi:10.3724/SP.J.1006.2023.22023

Abstract ( 443 )

HTML ( 28 )

PDF (414KB) ( 625 )

Save

Figures and Tables | References | Related Articles | Metrics

The side-deep fertilization of rice is an asymmetric local fertilization for rhizosphere of seedlings that fertilizers are applied deep in paddy soil. It has the advantages of reducing fertilizer application and labor cost, increasing fertilizer use efficiency and grain yield. However, the effects of side-deep fertilization on root characteristics and its relationship with grain yield are unclear. This field experiment was conducted using rice verities of Fengjing 1606 and Nanjing 9108. Four nitrogen treatments, conventional fertilization with common urea (CF), conventional fertilization with 15% reduction of control released fertilizer (CFCR), side-deep fertilization with 15% reduction of common urea (SDCU), and side-deep fertilization with 15% reduction of control released fertilizer (SDCR), were tested to explore the effects of different nitrogen treatments on root morphological traits, anatomical structure, physiological characteristics, and grain yield. The results showed as follows: (1) The grain yield of SDCR treatment was the highest, followed by CF and CFCR treatments, the yields of SDCU treatment was the lowest. (2) SDCR treatment significantly increased the total root length, the root tips, root surface area, and root volume at different growth stage. (3) SDCR treatment reduced the cortical cross-sectional area of rice roots, the cortical cell layers, and the root diameter, and increases the stele diameter at different growth stages, however, there was no significant effect on the aerenchyma area and cortical cell area. (4) Compared with CF treatment, SDCR treatment significantly improved rice root activity, root nitrogen metabolism enzyme activity increased and reached the peak at heading stage, and then decreased, SDCR treatment had the highest GOGAT and GS activities at different growth stages. Therefore, to improve rice yield, improve the fertilizer utilization efficiency, and achieve the purpose of nitrogen reduction and production increase, the side-deep fertilization with 15% reduction of control released fertilizer could improve root morphological traits, anatomical structure, and physiological characteristics, enhance the root ability to absorb nutrients and water, prevent premature senescence of plant.

Effects of wheat straw mulching on physical properties of topsoil and yield formation in soybean

WU Zong-Sheng, XU Cai-Long, LI Rui-Dong, XU Yi-Fan, SUN Shi, HAN Tian-Fu, SONG Wen-Wen, WU Cun-Xiang

Acta Agronomica Sinica. 2023, 49(4): 1052-1064. doi:10.3724/SP.J.1006.2023.24051

Abstract ( 429 )

HTML ( 16 )

PDF (965KB) ( 609 )

Save

Figures and Tables | References | Related Articles | Metrics

Huang-Huai-Hai Rivers region is the main producing area of soybean with high protein content in China. However, the previous wheat straw seriously restricts the production of summer soybean in this area. The traditional farming system with high input and low output cannot meet the demand for high-quality soybean. In this experiment, the soil temperature, soil moisture content, soil apparent density, and soil aggregate structure of the topsoil, yield and yield composition of soybean under different crop system were investigated. The aim of this study is to analyze the regulation mechanism of no-tillage combined with straw mulching on surface soil structure and soybean yield, and to provide theoretical reference for the selection of the best crop system for soybean in the Huang-Huai-Hai Rivers region. A split-plot experimental design was adopted in the experiment. The main plot was fertilizer treatment [fertilization (F: 225 kg hm^-2) and no fertilization (NF)]. The subplot was straw treatment [no-tillage without straw returning (SR), no-tillage with straw mulching (SM), and no-tillage with straw crushing returning (SC)]. The results showed that: (1) The effect of no-tillage combined with straw returning on the surface layer was mainly concentrated in soil depth of 0-10 cm. (2) Compared with SR, the soil temperature of SM and SC decreased by 0.21°C and 0.17°C, respectively. The soil water content increased by 13.18% and 9.07%, respectively. Compared with SR and SC, the soil apparent density of SM decreased by 2.61% and 2.87%, respectively, the solid phase proportion of the plough layer decreased by 2.60% and 3.01%, respectively, and the soil aggregate >2 mm increased by 6.84% and 3.14%, respectively. (3) Compared with SR, the number of pods per plant in SM and SC treatments increased by 22.41% and 9.49%, the 100-seed weight of soybean under SM and SC increased by 1.18% and 2.40%, while the number of grains per plant under SM and SC increased by18.20% and 7.51%, respectively. In addition, compared with SR, the yield and yield per plant were increased by 11.56% and 39.16% in SM and 5.43% and 18.07% in SC, respectively. In this study, the fertilization can promote yield increase effects on straw returning, and SM has a more significant yield increase effect than SC. In conclusion, no-tillage plus straw mulching and precise sowing cultivation technology for summer soybean after winter wheat has significant advantages in optimizing soybean root layer environment and promoting yield formation.

Effects of planting density on solar and heat resource utilization and yield of maize varieties at different growth stages

WU Xi, WANG Jia-Rui, HAO Miao-Yi, ZHANG Hong-Jun, ZHANG Ren-He

Acta Agronomica Sinica. 2023, 49(4): 1065-1078. doi:10.3724/SP.J.1006.2023.23032

Abstract ( 586 )

HTML ( 34 )

PDF (1113KB) ( 667 )

Save

Figures and Tables | References | Related Articles | Metrics

The objective of this study is to explore the response of maize solar and heat utilization, material production, and yield formation to density at different maturity stages, in order to provide a theoretical basis for high yield and efficiency cultivation of spring maize in Northern Shaanxi irrigation area. In 2019 and 2020, the field experiments were conducted by using two maize hybrids [Dongdan 60 (middle-late-maturing) and Dafeng 30 (middle-early-maturing)] with four planting density treatments [45,000 (D1), 60,000 (D2), 75,000 (D3), and 90,000 (D4) plants hm^-2]. Leaf area index, canopy solar distribution, material production and transport, solar and heat utilization, yield and its composition were measured. The results showed that, compared with the low density, Dafeng 30 and Dongdan 60 reached the highest yield of 18,787.5 kg hm^-2 and 16,953.0 kg hm^-2 under the density of 90,000 plants hm^-2 and 75,000 plants hm^-2 and increased by 37.7 % and 41.4 %, respectively. The grain moisture content of Dafeng 30 was 11.5 % lower than that of Dongdan 60 under high yield. With the increase of planting density, the leaf area index of the population and the interception rate of solar energy in the upper canopy increased significantly, while the solar interception rate of the middle canopy decreased significantly, and Dongdan 60 decreased more than Dafeng 30. There was no significant difference in the interception rate of the lower canopy. For the utilization of solar radiation, the pre-silking intercepted photosynthetically active radiation and radiation use efficiency of Dafeng 30 were 7.9% and 1.7% higher than those of Dongdan 60, respectively. The post-silking intercepted photosynthetically active radiation and radiation use efficiency of Dafeng 30 were 9.5% and 14.9% lower than those of Dongdan 60, respectively. The correlation between radiation use efficiency and planting density revealed that the increase of planting density was more obvious in improving the light radiation utilization efficiency of Dafeng 30. Under D4 density, the growth period of Dafeng 30 was shortened by 4.3 days on average compared with that of Dongdan 60, and the average effective accumulated temperature of Dafeng 30 was 25.3°C less than that of Dongdan 60, but the temperature use efficiency was 25.3% higher than that of Dongdan 60, and the accumulated temperature required to reach the maximum dry matter accumulation rate was less than that of Dongdan 60. The pre-anthesis dry matter accumulation and post-anthesis dry matter transport rate of Dongdan 60 and Dafeng 30 were 26.7%, 34.6%, and 43.7%, 55.8% higher than those of D1, respectively. The post-silking dry matter accumulation and post-silking dry matter transport rate of Dafeng 30 were 14.5% and 12.3% higher than those of Dongdan 60, respectively. In comclusion, the population structure of Dafeng 30 was reconstructed under the dense planting can improve solar energy interception in the middle canopy, increase growth rate of dry matter and advance dry matter to reach the maximum growth rate, promote dry matter accumulation and transportat, improve solar and heat resource utilization efficiency, and achieve high yield and efficiency of spring maize in this area. Meanwhile, the lower moisture content of grain was suitable for mechanical harvesting.

Effects of wheat-pea intercropping on population photosynthetic characteristics and crops productivity

WU Xiang-Qi, LIU Bo, ZHANG Wei, YANG Xue-Ni, GUO Zi-Yan, LIU Tie-Ning, ZHANG Xu-Dong, HAN Qing-Fang

Acta Agronomica Sinica. 2023, 49(4): 1079-1089. doi:10.3724/SP.J.1006.2023.21022

Abstract ( 342 )

HTML ( 18 )

PDF (820KB) ( 450 )

Save

Figures and Tables | References | Related Articles | Metrics

To investigate the effects of wheat and pea intercropping on population photosynthetic characteristics and productivity, a field experiment with two treatments [two strip cropping treatments of four rows of wheat + two rows of peas (W4P2), two rows of wheat + two rows of peas (W2P2), and single-crop wheat (CKW) and single-crop pea (CKP) as the controls] was conducted in Guanzhong region of Shaanxi Province from 2019 to 2021. The leaf photosynthetic rate (P_n), canopy apparent photosynthesis (CAP), dry matter accumulation and population productivity of wheat and pea were analyzed. The results showed that, compared with the monoculture, the W2P2 and W4P2 intercropping treatments significantly increased the SPAD and P_n of wheat leaves, but decreased the SPAD and P_n of pea leaves to different degrees. Intercropping wheat with peas significantly increased the preflowering population photosynthetic rate. The CAP of W4P2 increased by 6.2%-8.0% compared to its control population photosynthetic CAP_CK42 (2/3CAP_CKW+1/3CAP_CKP), while the CAP of W2P2 increased 6.2%-8.5% compared to its control population photosynthetic CAP_CK22 (1/2CAP_CKW+1/2CAP_CKP). Compared with CKW, the W4P2 and W2P2 intercropping treatments significantly enhanced the dry matter accumulation capacity per unit area of wheat, significantly increased the number of effective spikes and spikes at maturity stage, and increased the seed yield by 7.8%-9.4% and 18.9%-19.0%, respectively. Compared with CKP, the two intercropping treatments had a weakening trend in the dry matter accumulation and yield composition indexes of peas, and reduced the seed yield by 9.9%-12.2% and 6.8%-9.0%, respectively. The competitiveness evaluation revealed that the land equivalent ratios of W4P2 and W2P2 intercropping treatments were higher than 1 (W4P2: 1.02; W2P2: 1.06), indicating that wheat and pea intercropping increased the crop population yield advantage and the encroachment of the dominant crop wheat compared to pea was higher in the W2P2 intercropping model (0.27) than in W4P2 (0.20). In conclusion, in the wheat and pea intercropping system, compared to the broad-banded type (W4P2), the narrow-banded type (W2P2) was able to increase the population photosynthetic rate by increasing the photosynthetic capacity of the dominant crop wheat, thus promoting the use of light resources by the population and further exploiting the composite population production advantage.

Effects of nitrogen fertilizer application rate on starch contents and properties during storage root expansion in sweetpotato

WU Shi-Yu, CHEN Kuang-Ji, LYU Zun-Fu, XU Xi-Ming, PANG Lin-Jiang, LU Guo-Quan

Acta Agronomica Sinica. 2023, 49(4): 1090-1101. doi:10.3724/SP.J.1006.2023.24087

Abstract ( 417 )

HTML ( 25 )

PDF (977KB) ( 367 )

Save

Figures and Tables | References | Related Articles | Metrics

In order to explore the effect of nitrogen fertilizer application rate on starch contents and properties during storage root expansion of sweetpotato (Ipomoea batatas (L.) Lam.), two sweetpotato cultivars (‘Xinxiang’ and ‘Shangshu 19’) were taken as the experimental materials, and three nitrogen fertilizer application rates (0 kg hm^-2 (CK), 57.5 kg hm^-2 (N1), and 115 kg hm^-2 (N2)) were designed and conducted on the day of planting. To investigate the changes of starch content, starch gelatinization properties, starch dynamic rheological properties, gel texture properties, and amylase activity in sweetpotato storage roots during storage root expansion, the storage root samples were collected at the 60th, 80th, 100th, 120th, and 140th days after planting. Results were as follows: (1) Nitrogen fertilizer application could significantly increase the starch content of two cultivars during storage root expansion, but significantly reduce the hot paste viscosity (HPV), cold paste viscosity (CPV), and setback viscosity (SBV) of starch gelatinization properties of ‘Xinxiang’ at the initial stage of storage root expansion (IES), and significantly decrease the HPV, CPV, and SBV of ‘Shangshu 19’, while remarkably increase the HPV, CPV, and SBV of ‘Xinxiang’ at the late-expanding stage of storage root expansion (LES). (2) The hardness and chewiness of starch gel under three nitrogen fertilizer application treatments gradually decreased during storage root expansion. Among them, N2 treatment could significantly improve the hardness of gel of sweetpotatoes at LES. (3) The starch gel of two cultivars exhibit elastic properties. N1 and N2 treatments could increase the storage modulus and loss modulus of ‘Xinxiang’ whereas reduce the storage modulus and loss modulus of ‘Shangshu 19’. (4) Nitrogen fertilizer application rates reduced the amylase activity at IES, but increased the amylase activity at LES of the two cultivars. Therefore, nitrogen fertilizer application rate obviously affected the starch contents and properties of sweetpotatoes during storage root expansion. Moreover, ‘Shangshu 19’ with 115 kg hm^-2 of nitrogen fertilizer application rate harvesting on 120 days after planting, which was conducive to the processing properties of sweetpotato starch. In conclusion, reasonable nitrogen application and timely harvest were beneficial to the accumulation and quality improvement of sweetpotato starch.

Potato tuber greening evaluation based on RGB color space

WANG Shuo, BAO Tian-Yang, LIU Jian-Gang, DUAN Shao-Guang, JIAN Yin-Qiao, LI Guang-Cun, JIN Li-Ping, XU Jian-Fei

Acta Agronomica Sinica. 2023, 49(4): 1102-1110. doi:10.3724/SP.J.1006.2023.24078

Abstract ( 312 )

HTML ( 9 )

PDF (3207KB) ( 320 )

Save

Figures and Tables | References | Related Articles | Metrics

Potato is one of the most important crops in the world. Tuber is the commercial product of potato, whereas tuber greening seriously affects product quality and results in a large amount of potatoes waste. It is very necessary to establish a convenient evaluation method of tuber greening for the identification of potato germplasm resources and the analysis of tuber quality. In this study, we systematically evaluated the greening trend and greening degree of 15 potato tetraploid and diploid varieties (lines) base on the extraction of tuber color space characteristics and RGB color space color difference. Zhongshu 2, Zhongshu 18, Zhongshu 19, Atlantic, Favorita, and Kondor appeared faster greening speed, but HS66 appeared slower greening speed under 25℃ and 125 μmol m^-2 s^-1. Color difference value of tubers of all potato varieties (lines) tended to the stability after 9 days lighting treatment. There was an obvious greening extent differences among potato varieties (lines). Among them, the afforestation degree of Favorita was the highest, whereas Zhongshu 28 was the lowest after 13 days lighting treatment. The method established in this study can accurately distinguish the greening speed and the extent of different varieties (lines), which provided a convenient and reliable technical reference for tuber greening evaluation.

Effects of diverse mixture intercropping on the structure and function of bacterial communities in rice rhizosphere

TANG Wen-Qiang, ZHANG Wen-Long, ZHU Xiao-Qiao, DONG Bi-Zheng, LI Yong-Cheng, YANG Nan, ZHANG Yao, WANG Yun-Yue, HAN Guang-Yu

Acta Agronomica Sinica. 2023, 49(4): 1111-1121. doi:10.3724/SP.J.1006.2023.22001

Abstract ( 391 )

HTML ( 29 )

PDF (923KB) ( 414 )

Save

Figures and Tables | References | Related Articles | Metrics

In order to clarify the effects of mixture intercropping on the control of rice blast and the structure and function of the rhizosphere bacterial community, the 16S rRNA sequencing analysis of bacteria in rhizosphere soil of the selected high control efficiency (E=54.48%) (Shanyou 63/Huangkenuo) and low control efficiency (E=14.12%) combinations (Hexi 39/Huangkenuo) under the intercropping and monoculture treatments were performed with Illumina Hiseq sequencing technology. The results showed that soil bacteria, from 37 phyla, 116 classes, 244 orders, 384 families, 689 genera, were obtained in the intercropping system. Chloroflexi, Proteobacteria, and Actinobacteriota were the dominant bacterial groups. The relative abundance was higher than 15%. Alpha diversity analysis discovered that high-efficacy combination significantly increased the Shannon index and Chao1 index of rice rhizosphere bacterial community in intercropping conditions (P<0.05), whereas there was no difference at P>0.05 in low-efficiency combination. ANOSIM and PCoA analyses revealed that there was significant difference in the structure of the species in the rhizosphere bacterial community in monoculture (r = 0.48, P<0.01), but no significant difference in the rhizosphere bacterial community structure between the high- and low-efficiency combinations following intercropping (P>0.05), which indicating that intercropping increased the similarity of bacterial community structure between both combinations. Comparison to monoculture, the dominant bacterial group composition proved that the relative abundance of Shanyou63 Acidobacteriota decreased significantly, while the relative abundance of Shanyou 63 Actinobacteriota and Firmicutes increased significantly, but there was no significant difference among the dominant bacteria in Huangkenuo. Hexi 39 rhizosphere Patescilbacteria exhibited the significant decrease in low-efficiency combinations, whereas Gemmatimonadota showed the significant increase. PICRUSt2 function prediction discovered that the relative abundance of biosynthesis of other secondary metabolites in the main cultivars decreased significantly in the intercropping system, while the relative abundance of transcription, metabolism of cofactors and vitamins in intercropping cultivars increased significantly. In conclusion, to increase plant disease resistance and to provide data support for the theory of diverse intercropping for disease control, the high-efficacy combination had the ability to improve the diversity of rice rhizosphere bacteria and the structure and function of bacterial community by mixture intercropping, which effectively reduced the occurrence of rice blast and provided an application pathway for the improvement of soil microorganisms.

RESEARCH NOTES

Multi-disease resistance evaluation of spring maize varieties for the national regional test in Northeast and North China during 2016-2020

LUAN Yi, BAI Yan, LU Shi, LI Lei-Xin, WANG De-Qiang, GAO Ting-Ting, SHI Jie, YANG Hong-Ming, LU Ming

Acta Agronomica Sinica. 2023, 49(4): 1122-1131. doi:10.3724/SP.J.1006.2023.23031

Abstract ( 389 )

HTML ( 6 )

PDF (659KB) ( 383 )

Save

Figures and Tables | References | Related Articles | Metrics

Diseases have been major biological adversity affecting maize production. Developing disease resistant varieties is the most economical, effective, and environment-friendly strategy for maize disease prevention. In this study, the disease identification data of 724 tested varieties in the national regional test (early-medium maturity, medium maturity, and late-medium maturity) were analyzed in Northeast and North China from 2016 to 2020, including northern corn leaf blight, head smut, fusarium stalk rot, gray leaf spot, and fusarium ear rot. The results revealed that medium resistance and susceptibility dominated the five disease resistance categories, accounting for 82.94%, 84.12%, and 72.46% in the early-medium maturity, medium maturity, and late-medium maturity groups, respectively. The varieties with early-medium maturity, medium maturity, and late-medium maturity groups with medium resistance (MR) or above accounted for 50.24%, 56.37%, and 69.33% of the total varieties, with high resistance (HR) accounting for 4.52%, 4.41%, and 7.84% of the total, respectively. Northern corn leaf blight and gray leaf spot antigens were few, and no high-resistance varieties existed. Fusarium stalk rot, head smut, fusarium ear rot, gray leaf spot, and northern corn leaf blight were ranked from high to low in terms of resistance (R) in early-medium maturity. The medium maturity group was fusarium ear rot, fusarium stalk rot, head smut, gray leaf spot, and northern corn leaf blight. The order of late-medium maturity group was fusarium ear rot, fusarium stalk rot, head smut, northern corn leaf blight, and gray leaf spot, respectively. Climate and environment had an impact on inter-annual identification results, and the overall performance in 2020 was worse. The varieties with the five kinds of diseases in the early-medium maturity, medium maturity, and late-medium maturity groups reaching the medium resistance (MR) or above at the same time accounted for 2.78%, 6.37%, and 15.67%, respectively. However, only one variety (Chengyu 88) passed the test, demonstrating that breeding high yielding, disease-resistant green maize variants was challenging. It was recommended that a disease-resistant green maize variety test group could be established, that disease-resistant green maize varieties be identified more successfully, and that green maize varieties be promoted more effectively and rapidly. This study clarifies the main disease resistance level of northeast and north spring maize test varieties in recent year, and provides a reference for future variety breeding, validation, and promotion, so as to support the green development of China’s maize seed industry.

Identification and evaluation of wheat germplasm resources at seedling stage

SUN Xian-Jun, JIANG Qi-Yan, HU Zheng, LI Hong-Bo, PANG Bin-Shuang, ZHANG Feng-Ting, ZHANG Sheng-Quan, ZHANG Hui

Acta Agronomica Sinica. 2023, 49(4): 1132-1139. doi:10.3724/SP.J.1006.2023.21021

Abstract ( 591 )

HTML ( 28 )

PDF (441KB) ( 1033 )

Save

Figures and Tables | References | Related Articles | Metrics

Soil salinization is one of the important abiotic stresses which affects wheat growth. The screening and breeding salt-tolerant wheat is of great significance to the utilization of salinized land. 19 hybrid wheat resources and 2 conventional varieties were used as the experimental materials, seeds were grown in vermiculite, 6 treatments of NaCl solutions with 0, 0.4%, 0.8%, 1.2%, 1.6%, and 2.0% from sowing were set, and 11 indicators related to the growth were analyzed and determined. The multivariate statistical analysis method was used to evaluate the salt-tolerant of wheat germplasm resources at seedling stage. The results showed that the saline tolerance coefficient of most indicators were the highest interquartile range under 1.2% salinity among germplasm resources, thus the 1.2% salinity was considered as the optimum concentration for identification saline tolerance. 11 indicators could be simplified into 3 principal components by using principal component analysis. Through the analysis of principal component contribution rate and membership function, the 3 principal component values were further reduced to D-value of comprehensive evaluation index. According to the D-value, 21 wheat germplasm resources were divided into 5 salt-tolerant levels (high tolerance, salt tolerance, medium tolerance, sensitive and high sensitivity) by cluster analysis. The comprehensive evaluation D-values of 13 hybrid wheat varieties were higher than that of Jiemai 19 and Jimai 22 at seedling stage. Combined with stepwise regression analysis, the optimal regression equation of salt-tolerant coefficient and D-value of 11 indicators was obtained: D= -0.743 + 0.779×PLL + 0.372×TNL + 1.273×PH + 0.336×PLC + 0.279×RL + 0.558×RDW. Based on the above regression equation, PLL (penultimate leaf length), PH (plant height), PLC (penultimate leaf chlorophyll), RL (root length), and RDW (root dry weight), could be used as evaluation indicators for wheat germplasm resources identification under 1.2% continuous salt stress at seedling stage.

Optimization of field configuration technology of strip intercropping of fresh corn and fresh soybean based on high yield and high efficiency

SHU Ze-Bing, LUO Wan-Yu, PU Tian, CHEN Guo-Peng, LIANG Bing, YANG Wen-Yu, WANG Xiao-Chun

Acta Agronomica Sinica. 2023, 49(4): 1140-1150. doi:10.3724/SP.J.1006.2023.23013

Abstract ( 474 )

HTML ( 28 )

PDF (3287KB) ( 270 )

Save

Figures and Tables | References | Related Articles | Metrics

To clarify the high yield of strip intercropping of fresh corn and fresh soybean in Southwest China and to realize efficient field configuration technology for mechanization, two fresh corn varieties with large plant height differences were used as the materials, and two factor split zone design was adopted. The effects of two kinds of bandwidth (high-yield bandwidth 2 m and high-efficiency bandwidth suitable for mechanization 2.4 m) and maize planting density (37,500, 45,000, 52,500, and 60,000 plants hm^-2) on population yield, commodity quality, and planting benefit in the strip intercropping system of fresh corn and soybean were comprehensively analyzed, and the optimal field configuration of high-yield and high-efficiency was determined. The results showed that the yield of fresh corn and fresh soybean were more affected by corn planting density and bandwidth, respectively. With the increase of bandwidth, the first-class ear rate of dwarf maize varieties decreased by 25.78%, the bald tip length increased by 9.55%, and the first-class ear rate of tall maize varieties decreased by 11.76% and the bald tip length increased by 17.54%. With the increase of maize density, the first-class ear rate, bald tip length of dwarf, and tall maize varieties decreased significantly under the two bandwidth, and the planting density of dwarf and tall maize increased from 52,500 plants hm^-2to 60,000 plants hm^-2 in 2019. The first-class ear rate decreased by 46.16% and 27.78%, the bald tip length increased by 19.44% and 14.17%, and the first-class ear rate decreased by 25.01% and 23.60% under the 2.4 m bandwidth, and the bald tip length increased by 16.46% and 11.53%, respectively. The effects of bandwidth and density on the 2-pod rate and 3-pod rate of fresh soybean reached a significant level. With the increase of bandwidth, the 2-pod rate and 3-pod rate of strip intercropping soybean increased significantly. The 2-pod rate and 3-pod rate of soybean intercropped with dwarf and high stalk maize varieties increased by 7.94% and 18.88%, 8.10% and 16.71%, respectively. With the increase of corn density, the 2-pod rate and 3-pod rate of soybean decreased significantly. In 2019, the corn density increased from 52,500 plants hm^-2 to 60,000 plants hm^-2. The 2-pod rate of soybean intercropped with high stalk corn decreased by 6.19%-9.09%, and the 3-pod rate decreased by 11.94%-14.39%. The comprehensive evaluation score of principal component and DTOPSIS method showed that under the high-yield and high-efficiency bandwidth, the corn density of 52,500 plants hm^-2 and 45,000 plants hm^-2 of strip intercropping fresh soybean of dwarf and tall maize varieties were close to the ideal value of maize density, the comprehensive characters performance was good. The planting benefits could reach 84,400 Yuan hm^-2 and 100,900 Yuan hm^-2, respectively.