Table of Content

12 March 2006, Volume 32 Issue 03

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ORIGINAL PAPERS

Reflectance Distribution of Corn Canopies Simulated with Radiosity-graphics Combined Model

XIE Dong-Hui; SUN Rui; ZHU Qi-Jiang;WANG Jin-Di;WU Men-Xin;QIN Wen-Han

Acta Agron Sin. 2006, 32(03):  317-323. 

Abstract ( 1913 )   PDF (588KB) ( 1264 )   Save

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In the research of quantitative remote sensing, bidirectional reflectance distribution function (BRDF) of the Earth surface are important to understand the course and mechanism of the interaction between light and vegetation. And according to the principles of the BRDF models, physical models of vegetation in the field of remote sensing can be divided into three categories: geometry optical models (GO), radiance transfer models (RT) and computer simulation model. The computer simulation models, for instance, Monte Carlo, ray-tracing and radiosity, are paid more attention with the development of computer technology. The radiosity method is a powerful tool to describe the reflectance distribution from the canopies, which can take much more detailed structures of vegetations and the course of reflectance, transmittance and multiple-reflectance between the components in the scenes into account and help to understand and simulate the radiation distribution of canopies.
In this study, summer corn was selected as an example and light distributions in the canopy were simulated with RGM (radiosity-graphics combined model). First, three dimensional structures of corns were rendered with the modified extended L-systems (MELS) method using the statistical parameters measured in the field at Luancheng ecosystem station of Chinese academy of science, located at Hebei Province in 2000（Longitude: 37º52´N，latitude: 114º39´E，altitude: 50.5 m）. Second, RGM, which can take much more detailed structures of vegetation canopies into account, was analyzed and applied to simulate the radiance distribution in the corn canopy. Finally, results of BRF simulated by RGM model were compared with those measured data in the field. They were both agreed well. Therefore, BRF simulated by the model can be used to supply the spectrum database or to supplement measured data. The intermediate result of simulation can also be use to analyze APAR in the canopy as well.

Identification of Gly m Bd 28K and Gly m Bd 30K Lacking Soybean by Using Random Sampling of Core Collection in Soybean

ZHANG Yue-Qiang;GUAN Rong-Xia;LIU Zhang-Xiong;CHANG Ru-Zhen;YAO Yuan-Song;QIU Li-Juan

Acta Agron Sin. 2006, 32(03):  324-329. 

Abstract ( 2163 )   PDF (1049KB) ( 1134 )   Save

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Soybean core collection is very important foundation for novel gene mining. Part of soybean core collection was used to compare with reserved germplasm and wild soybean by using immunoblotting, in order to select Gly m Bd 30K and Gly m Bd 28K allergen-null germplasm, and evaluate the representation of core collection. The result showed that all the materials, including 60 wild soybean and 421 cultivars, contained Gly m Bd 30K and the absence ratio of Gly m Bd 28K in cultivars (37.8%) was higher than that in wild soybean (13.3%). The distribution tends of Gly m Bd 28K null materials in core collection was similar to that in reserved collection. The absence ratios of Gly m Bd 28K were not significantly different in three ecotype regions of both core collection and conserved collection, which indicated that the core collection has perfect representative. SSR marker analysis showed that similarity index among 80% cultivars lacking Gly m Bd 28K was less than 0.44, which indicated these germplasms had abundant genetic diversity and could be used in the breeding of Gly m Bd 28K lacking varieties.

Effects of Water Deficiency on the Activities of Key Enzymes Involved in the Starch Synthesis and the Accumulation of Starch for the Transgenic Rice Plants Carrying Antisense Wx gene during Grain Filling

CAI Yi-Xia;WANG Wei;ZHANG Zu-Jian;ZHU Qing-Sen;YANG Jian-Chang

Acta Agron Sin. 2006, 32(03):  330-338. 

Abstract ( 1876 )   PDF (554KB) ( 996 )   Save

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Soil drought is one of the most important factors limiting rice production in china. Recently, more attention for the inferior quality of rice caused by water stress has been paid in agricultural production. The previous study showed that the indices of quality, such as chalkiness, gel consistency and RVA profile were changed by soil drought. It is considered that rice quality is related to the process of starch accumulation. Therefore, all changes of rice quality under water deficit conditions are responsible for physiological metabolism of starch accumulation during grain filling. In present study, the pot experiments were conducted at Yangzhou University. Three transgenic rice plants CA1, CA2, CA3 carrying antisense Wx gene and a wild type (cv. Wuyunjing7) were grown under water deficiency at flowering stage. In order to assess the implication of physiological metabolism of starch accumulation to water deficiency, as the indictors of rice quality, the contents of soluble sugar, starch, amylose and amylopectin were measured. The starch accumulation capacity was determined by measuring adenosine diphosphoglucose pyrophosphorylase (ADPGPase), soluble starch synthase (SSS), granule-bounding starch synthase (GBSS), starch branching enzyme (Q-enzyme) and two debranching enzymes (Isoamylase and Pullulanase) in rice grain during filling period. The results showed that the activities of ADPGPase and GBSS were significantly enhanced at initial filling stage (5~10 d), and then declined rapidly from 20 days after anthesis (DAA) to ripening (Fig.1) by drought stress. The maximum activity of SSS was significantly decreased, but less affected by water deficiency at the later stage of starch accumulation. Q enzyme catalyzed the formation of α-1, 6 indican bond involved in the synthesis of amylopectin was most sensitive to water in that it responded earlier, and to a greater extent, than the other enzymes. The significant decrease in activity of Q enzyme was observed under water-deficit conditions, especially in later grain-filling stage (Fig.2). However, under such drought conditions, leading to decrease of starch accumulation, the decline in Q enzyme activity was more than that in ADPGPase and SSS. The activities of two debranching enzymes (DBE, Isoamylase and Pullulanase) were elevated significantly, and the high activity of Pullulanase was substantially observed at 20-30DAA under water deficiency (Fig.3). The total accumulation of starch and the content of amylopectin were reduced under water deficiency compared to well-watered treatments (Fig.4, Fig.5). A positive correlation between the maximal activity of GBSS and the content of amylose was observed (r=0.981**). However, there were no clear correlations between the maximal activities of SSS, Q enzyme, DBE and starch content or amylopectin content. The results suggested that the influences of soil water potential on starch accumulation and the synthesis of the amylopectin were attributed to changes of activities in SSS, Q-enzyme, DBE and other enzymes, and not regulated by only one of them.

Effects of Phosphorus on Activities of Enzymes Related to Nitrogen Metabolism in Flag Leaves and Protein Contents in Grains of Wheat

WANG Xu-Dong;Yu Zhen-Wen;SHI Yu;WANG Xiao-Yan

Acta Agron Sin. 2006, 32(03):  339-344. 

Abstract ( 1826 )   PDF (485KB) ( 1042 )   Save

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Nitrogen metabolism in leaves has important function on protein accumulation in wheat grains, involving three key enzymes, i.e. nitrate reductase (NR), glutamine synthetase (GS) and endopeptidase (EP). It has been well documented the changes of related enzymes in nitrogen metabolism under different rates of nitrogen and potassium fertilizer. However, little research has been done about the effect of phosphorus (P) on the contents of protein components in wheat. The objectives of the present research were to investigate the effect of P on the activities of three enzymes concerned with nitrogen metabolism in flag leaves and protein accumulation as well as its component contents in wheat grains. The study was carried out from 2001 to 2002 with two wheat cultivars (Triticum aestivum L. cv. Lumai 22 and cv. Jinan 17) in field. Three P rates (P0, P1 and P2) were set in the experiment, and the amounts of P application were 0 kg, 105 kg and 210 kg P₂O₅ per ha, respectively. The results showed that the activities of NR, GS and EP in flag leaves were increased with the increase of P application during the early and middle grain filling stages (Fig.1-3), and the effect of P application for Jinan 17 was greater than that for Lumai 22, but there was no significant difference between P₁ and P₂ treatment. The contents of soluble protein and free amino acid in flag leaves were increased by P application before 14 d and 7 d after anthesis respectively（Fig.4 and Fig.5）. And P1 treatment was of benefit to the accumulation of free amino acid during early grain filling stage and the redistribution to grains during the whole grain filling stage, whereas P2 treatment was less effect on the redistribution. It indicated that the synthesis and accumulation of protein in grains were increased by P application during grain filling stage, especially in the early stage. The protein content in P₁ and P₂ was significantly higher than that in P₀ during the early grain filling. When maturing, P₁ treatment had the highest total protein content in both cultivars (Fig.6). In P1 treatment there were little effect on the contents of albumin and globulin, and significant increase for the contents of gliadin and gluten in the two cultivars, which was greater for Lumai 22 than for Jinan 17 (Table 1). These results suggested that P1 treatment had little effect on wheat nutritional quality, but could improve its processing quality. However, excessive P application could deteriorate the processing quality as for Jinan 17. Therefore, different cultivation management should be adopted according to the different quality demans of different wheat types.

Effects of Nitrogen Application on Nitrate Accumulation and Yield of Euchlaena mexicana

WANG Yong-Jun; WANG Kong-Jun; DONG Shu-Ting;HU Chang-Hao;ZHANG Ji-Wang;LIU Peng

Acta Agron Sin. 2006, 32(03):  345-350. 

Abstract ( 2403 )   PDF (463KB) ( 1104 )   Save

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Euchlaena mexicana is one of forage crops with high yield and high quality, which has been introduced from Japan since 1979. In forage cultivation, mass nitrogen fertilizer are generally applied in order to gain high yield, but over-use of nitrogen will reduce the quality of forage crops, and cause negative effects to the environment as well. A micro-plot experiment was carried out to study the effects of nitrogen application on nitrate (NO₃^--N) accumulation and yield of E. mexicana. In this experiment, four treatments induced two levels of nitrogen rate (the middle level of 300 kg/ha and the high level of 600 kg/ha), and two modes of nitrogen application (all nitrogen applied as basic fertilizer, and another applied averagely at three times). During the whole growth season, the plants were mowed three times on August 10^th (H₁), September 11^th (H₂) and October 12^th (H₃), respectively, and the plant height was about 110 cm at every harvest stage. Nitrogen fertilizer was applied as dressing at H₁ and H₂ after mowing. The NO₃^--N concentrations of the newly leaves, fully expanded leaves, old leaves, stalks and roots were determined. The results showed that the NO₃^--N concentration was high in the newly leaves, low in the fully expanded leaves and middle in the old leaves. The concentrations of NO₃^--N in both stalks and roots were lower than those in all the leaves on H₁ and in newly leaves on H₂, but higher than those in all leaves on H₃. With the increase of harvest times, the concentration of NO₃^--N was decreased in all leaves. However, the concentrations of NO₃^--N in stalks and roots were decreased on H₂ and increased on H₃. The treatment of high nitrogen and applied averagely three times led to NO₃^--N accumulation largely in the same type of leaves. In the treatment of N_2-3 (600 kg/ha averagely applied three times), the NO₃^--N concentration of the newly leaves was 92.66 mg/g, which was the highest in the three types of leaves on H₂, and was still lower than the potential toxicosis dose for animals. With the increase of nitrogen rate, the nitrogen utilization efficiency (NUE) reduced, but the dry matter yield and crude protein yield of high nitrogen treatment (600 kg/ha, applied as basic fertilizer) were significantly higher than that of any other treatment. It comes to a conclusion in E. mexicana production practice, high basic nitrogen fertilizer may tend to high forage yield and be safe to livestocks.

The Cytological and Fertility Studies on Intersubgenomic Hybrids (ArAnCcCn) in Brassica napus

LI Mao-Teng; WANHG Fang; ZHANG Chun-Yu;MENG Jin-Ling

Acta Agron Sin. 2006, 32(03):  351-357. 

Abstract ( 1901 )   PDF (730KB) ( 1148 )   Save

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It was found that there were strong correlations between genetic distance and mid parent heterosis for seed yield in rapeseed. So the increasement of genetic diversity of B. napus is an important way to increase the yield of oilseed rape. There are two strategies to enhance the diversity of B. napus. One is to resynthesize B. napus artificially by sexual or somatic hybridization between B. rapa and B. oleracea, another is to introduce good characters of other Cruciferae materials into B. napus. However, multivalent or univalent formation at meiosis result in low fertility and low seed setting in these resynthesized lines, which were less direct utilized in seed production. In order to overcome this shortcoming, a new breeding strategy was conducted in our experiment, using the plants with 38 chromosomes (A^rA^rC^cC^c) selected from the progenies of pentaploid hybrids (A^rAⁿB^cCⁿC^c) derived from the hybridization between hexaploid (A^rA^rB^cB^cC^cC^c) and natural B. napus (AⁿAⁿCnCn). Intersubgenomic hybrids of rapeseed were produced by hybridization between the novel genotype B. napus (A^rA^rC^cC^c) and natural B. napus, Xiangyou 15 (AⁿAⁿCⁿCⁿ). The cytological studies on the intersubgenomic hybrids (A^rAⁿC^cCⁿ) revealed that the main chromosome configuration of pollen mate cell (PMCs) was 19 bivalents, the trivalents and quarivalents were also appeared in some cases at metaphase Ⅰ. The assessments of homologous chromosomes and chromosome monads at anaphase Ⅰ and anaphase Ⅱ were normal except for some laggards that were observed in a few cases. It indicated that the chromosome pair of A^r/Aⁿ and C^c/Cⁿ in the intersubgenomic hybrids could be normally paired in most cases. The genetic differentiation of subgenomes between A^r and Aⁿ may influence the meiosis of intersubgenomic hybrids.

Quantitative Relationship between Leaf Nitrogen Concentration and Canopy Reflectance Spectra

LI Ying-Xue; ZHU Yan; TIAN Yong-Chao; YAO Xia; QIN Xiao-Dong and CAO Wei-Xing

Acta Agron Sin. 2006, 32(03):  358-362. 

Abstract ( 1902 )   PDF (455KB) ( 1133 )   Save

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Experiment one was conducted with two cultivars (Xuzhou 26 and Huaimai 18) and four N application levels of 0, 120, 210 and 300 kg·ha^-1 in 2001. Experiment two was designed for one cultivar, Yangmai 10, with three N application levels of 0, 150 and 300 kg·ha^-1 in 2002. Experiment three included four cultivars (Xuzhou 26, Huaimai 20, Ningmai 9 and Yangmai 10) with five nitrogen levels of 0, 75, 150, 225, 300 kg·ha^-1 in 2003. On the basis of characterized protein content of these five cultivars, Xuzhou 26 and Ningmai 9 were considered as high and low protein types, respectively, and the other three cultivars were thought to be medium-protein type.
The results showed that the nitrogen concentration in wheat leaves was increased with increasing nitrogen fertilizer, whereas the canopy reflectance was also significantly different under varied nitrogen application. For the different cultivar types with low, medium and high grain protein contents, the relationships of leaf nitrogen concentration to NDVI (1220, 710) and red edge position of canopy reflectance spectra were all highly significant with R2 of 0.80(Fig.1 and Fig.2). An integrated regression equation could be used to describe the dynamic change pattern of leaf nitrogen concentration with reflectance spectra parameters in different cultivar types, although separate regression coefficients enhanced the prediction accuracy in low protein type. The above dynamic relationships of leaf nitrogen concentration to canopy reflectance spectra were feasible for different cultivars, growing stages and nitrogen levels in wheat. These results provide a theoretical basis and technical approach for monitoring of plant nitrogen status and precision management of nitrogen fertilization in wheat production.

Nitrogen, Phosphorus and Potassium Absorption in Ensilage Maize

GAO Ju-Lin;WANG Zhi-Gang;SUN Ji-Ying;CUI Cai;ZHANG Yong-Ping and LIU Ke-Li

Acta Agron Sin. 2006, 32(03):  363-368. 

Abstract ( 2051 )   PDF (479KB) ( 1176 )   Save

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There have been many reports about the requirements of nitrogen, phosphorus and potassium in grain maize, but seldom in ensilage maize. The objectives of this research were to compare the N,P,K requirements among grain maize,grain-forage maize and ensilage maize, and to provide a guide of fertilizer application for high yielding and high effective cultivation of ensilage maize.The N,P₂O₅ and K₂O contents absorption and accumulation amounts and absorption ratio in the plants were measured and the results showed that nitrogen and phosphorus contents in ensilage maize were different from that in grain maize.The nitrogen contents of ensilage maize showed a unimodal curve during the growing stage,and reached the maximum at 55 d after seedling emergence.The phosphorus contents were relatively stable,and the potassium contents decreased gradually in the process of growth.The ensilage maize required more nitrogen, phosphorus and especially more potassium than grain-forage maize.The suitable fertilization ration was N︰P₂O₅︰K₂O=(2.74±0.14)︰1︰(5.94±0.82), and the demands for N, P₂O₅ and K₂O per 100 kg dry matter produced were (0.57±0.05) kg, (0.26±0.03) kg and (1.58±0.12) kg, respectively. The demand of N and P₂O₅ per 100 kg dry matter was grain maize cultivar＞grain-forage maize cultivar＞ensilage maize cultivar, and that of K₂O was ensilage maize cultivar＞grain-forage maize cultivar＞grain maize cultivar.It indicates that ensilage maize has higher dry matter production efficency.

Cytoplasmic Male-Sterility of Onion (Allium cepa L.) 63A Is Associated with Premature Degeneration of the Tapetum

LI Yuan-Yuan; YANG Qing; YAN Ji-Yong and CHEN Min

Acta Agron Sin. 2006, 32(03):  369-372. 

Abstract ( 1764 )   PDF (950KB) ( 922 )   Save

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Cytological studies of cytoplasmic male-sterility (CMS) mechanism have been reported in several crops of Arabidopsis, soybean, rice, wheat etc. To date no report on CMS studies in onion (Allium cepa L.) is available in China. By using the technology of light microscopy and transmission electron microscopy, microstructural and ultrastructural observations of male-sterility line 63A and maintainer line 63B anthers were done during their development in onion (Allium cepa L.). The results indicated that in the male sterile anther, pollen sacs were formed irregularly and the tapetum formation was incomplete at the pollen-mother cell stage. The middle layer was degenerated completely and collapsed into a thin layer, the tapetal cells become vacuolated and dissociated from the pollen sac wall, followed by condensation of the tapetal cytoplasm at the tetrad stage. Meanwhile, it was presumed that the tapetal cells in male sterile anther underwent premature programmed cell death (PCD) based on the DNA ladder. At the developing microspore stage, the complete disintegration of cytoplasm in the microspore was observed. It is suggested that the microspore abortion in male-sterile anther would be attributed to premature degeneration of middle layer and tapetum.

Genetic Diversity and Genetic Relatives Analysis of Tobacco Germplasm Based on Inter-simple Sequence Repeat (ISSR)

QI Jian-Min;WANG Tao;CHEN Shun-Hui;ZHOU Dong-Xin; FANG Ping-Ping;TAO Ai-Fen;LIANG Jing-Xia and WU Wei-Ren

Acta Agron Sin. 2006, 32(03):  373-378. 

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Genetic diversity and relationships of tobacco is a basic part of the research in breeding, origin and evolvement of tobacco. Sixteen primers were selected from 70 ISSR primers, and 309 DNA fragments were amplified from 30 samples including 3 wild species and 1 cultivated species. Of which, 288 fragments were polymorphic (percentage of polymorphic bands was 93.20%), and the average number of DNA bands was 19.31 per primer. The genetic similarity among all species ranged from 0.26 to 0.96, and that among 3 wild species N.glutinosa, N.suaveolens and N.Gossei was 0.29–0.52, while among cultivars was 0.54–0.96, which was comparatively higher. This indicated that the genetic basis was comparatively narrow among the cultivars, except Bailei 21, Taiyan 7 and other materials. The cluster analysis based on ISSR markers showed that the 3 wild species were genetically different from the other 27 cultivars at the level of D=0.475, and the 30 tobacco accessions could be classified into two groups, three classes and six types at the level of D=0.776. The results indicated that ISSR technique has better stability than RAPD and is useful in revealing the genetic diversity and genetic relationships among tobacco species, providing a scientific basis for genetic research and tobacco breeding, as well as for gene cloning of plant germplasm and parents selection in constructing genetic linkage map of tobacco.

Comparison on the Main Agronomical and Quality Characters between Japonica Cultivars with Different Panicle Types in Jiang-Huai Area

XU Da-Yong; DU Yong; FANG Zhao-Wei; PAN Qi- Min; YONG Jian-Chang and ZHU Qing- Sen

Acta Agron Sin. 2006, 32(03):  379-384. 

Abstract ( 1960 )   PDF (453KB) ( 1182 )   Save

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Thirty six japonica cultivars bred in Jiang-Huai area were categorized into three groups with semi-dense panicle, near-dense panicle and dense panicle by clustering analysis, based on panicle grain density. With the panicle type changing from thin panicle to semi-dense panicle and dense panicle the rice cultivars were changed as follows: total grain numbers and filled grain numbers per panicle, the diurnal yield were improved significantly while panicle numbers/m², 1000-grain-weight and the percentage of filled grains declined; plant height was increased, top three leaves became longer and wider, biological production per day was increased; the first and second branches of the panicle and grain density were increased; some values of physiological character were increased, such as nitrogen content and chlorophyll content of leaf, and nitrogen content of stem during heading and maturity stages; As to some grain quality characters, the rate of brown rice and head milled rice, chalkiness rate were decreased, gel consistency became rigid and protein content was increased.

QTL Mapping for Callus Induction and Plant Regeneration in Maize Immature Embryos

ZHANG Hong-Wei;LIU Ya-Juan;GUO Xiao-Lin;ZHANG Feng;LI Jian-Sheng;TAN Zhen-Bo;CHEN Gang;SUN Dong-Fa

Acta Agron Sin. 2006, 32(03):  385-389. 

Abstract ( 1789 )   PDF (440KB) ( 990 )   Save

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Inbred lines Huangzao4 and Mo17 were used to develop a population consisted of 239 Recombinant inbred lines（RILs）. Based on the F8 generation population, a SSR linkage map was constructed with 101 SSR loci, covering maize genome 1 422.7 cM with an average interval length of 15.6 cM. The 239 RILs and their parental lines were evaluated for tissue cultural traits，including calli initiation frequency, type Ⅱ calli initiation frequency, green buds initiation frequency and plant regeneration frequency. With the method of composite interval mapping, 8 QTLs were identified and located on chromosome 2, 3, 5, 6, 8 and 9. 5 QTLs of regeneration frequency were identified on chromosome 2, 3, 5, 6, and 9, which can explained 6.29%, 5.19%, 7.88%, 14.02% and 10.4% of the phenotypic variance, respectively. 1 QTL on chromosome 5, linked with markers umc1966 was identified with minor effects conferring type Ⅱ calli initiation frequency, which only explained 6.60% of the phenotypic variance. 2 QTLs on chromosome 8, linked with markers bnlg2235 and bnlg240, were identified controlling calli initiation frequency and green buds initiation frequency, which explained 9.51% and 4.78% of the phenotypic variance, respectively. Two QTLs controlling type Ⅱ callus rate and plant regeneration rate were located in the neighboring region of chromsome 8, and these two traits were correlated between each other. However, further study is needed to make clear if the correlation is due to one pleiotropic gene or the linkage of two genes.

The Morphological Characteristics and Its Types of Yunjie (Eruca sativa Mill.) in China

SUN Wan-Cang; GUAN Chun-Yun; MENG Ya-Xiong; LIU Zi-Gang; ZHANG Tao; ZHANG Jin-Wen; CHEN She-Yuan; FAN Hui-Ning; WANG Bao-Cheng; SHAO Deng-Kui; WU Jun-Yan; YAN Ni and ZHU Hui-Xia

Acta Agron Sin. 2006, 32(03):  390-396. 

Abstract ( 1938 )   PDF (1046KB) ( 1013 )   Save

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Twenty classic landraces of Yunjie(Eruca sativa Mill.) from 9 Provinces and regions of China were selected based on the morphological characteristics. The Yunjie genetic resources can be divided into two types, i.e. entire leaf Yunjie and pinnatinnately parted leaf Yunjie. Hetian Yunjie is belonged to the former and the others to the latter. A dendrogram based on ten morphological characteristics showed that Hetian Yunjie was distinguished from other Yunjie in this study. Hetian Yunjie has hair-free stem, radical and stem with entire leaves with stipes and which are 9.0 cm long and 0.5 cm wide. Its netted venation on petals is green and its hair-free which is quardrangular in sections while the Chinese Yunjie has pinnately parted leaf with purple-brown netted venation and cylindrical-like fruits. Clusting based on RAPD analysis also showed the correspondence with the result based on the inophological characters. On the other hand, there were a cross-compatibility between Hetian Yunjie and other Yunjie and the nearly same mature period among the tested Yunjie accessions. It was reveal that Hetian is the new type of Chinese Yunjie and its systematic level should be studied in future, possibly, it is the new type of variety or subspecies of E. sativa.

Development of NILs with Cl-gene of Rice Restorer and Evaluation on the Near-isogenic level

ZHANG Yi; LI Yun-Feng; XIE Rong; YANG Zheng-Lin; ZHONG Bing-Qiang; SHEN Fu-Cheng; TAN Zi-Jun and HE Guang-Hua

Acta Agron Sin. 2006, 32(03):  397-401. 

Abstract ( 1960 )   PDF (1006KB) ( 1153 )   Save

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The anatomization, effects on agronomic characters, inheritance and gene location of clustered character in different rice resources have been analyzed by some researchers. Z1820, a new spontaneous mutant with clustered spikelets gene (Cl-gene), was founded in breeding materials. Restorers (LH17 and N45) as recurrent female parents and Z1820 as non-recurrent parent, two NILs (Cl-LH17 and Cl-N45) were obtained in the purpose of studying the effects on agronomic characters, gene location of this Cl-gene. The method of morphologic comparability and the technology of SSR marker were introduced into the polymorphism analysis and the near-isogenic level evaluation on those two pairs of Cl-NILs. The main results are as follow: (1) For LH17 and Cl-LH17, there was significant difference in plant height and panicle length but not in effective tillers per plant, spikelets per panicle and percentage of grain setting; for N45 and Cl-N45, there was significant difference only in panicle length (Table 1). (2) Among the detected 120 pairs of SSR primers (10 pairs every chromosome), only RM7434 on chromosome was amplified polymorphic bands between LH17 and Cl-LH17, but there are four primers (RM6297 ,on chromosome; RM587, 7434 ,on chromosome 6; RM3583, chromosome 7) which were produced polymorphic bands in N45 and Cl-N45; Another four SSR primers near RM7434 were produced polymorphic bands in NILs and their recurrent parents, and RM5957 was a polymorphic primer to LH17 and Cl-LH17 but not to N45 and Cl-N45. (3) The numbers of double, three and four-clustered spikelets in Cl-N45 were all bigger than those in Cl-LH17 and the clustering level (based on clustered rate) of Cl-N45 was also bigger than that of Cl-LH17. Those results indicated that the plant height and panicle length were decreased by Cl-gene from Z1820 but effective tillers per plant, spikelets per panicle, and percentage of grain setting were not changed; LH17 and Cl-LH17 are one pair of ideal Cl-NILs and they can be propitious to be used in the lucubration of the Cl-gene; the spikelets-clustered phenotype was different in different genetic background. The high quality NILs can be easily developed and the near-isogenic level can be objectively evaluated by the combining utilization of classical methods and modern molecular marker technologies.

Effects of Sowing Density, Fertilizer Amount in Seedbed and Seedling Age on Seedling Quality and Grain Yield in Paddy Field for Mechanical Transplanting Rice

SHEN Jian-Hui; SHAO Wen-Juan; ZHANG Zu-Jian; JING Qi-Jian; YANG Jian-Chang; CHEN Wen-Lin and ZHU Qin-Sen

Acta Agron Sin. 2006, 32(03):  402-409. 

Abstract ( 2042 )   PDF (577KB) ( 1034 )   Save

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An experiment of two factors(sowing density and fertilizer amount in seedbed) was conducted in plastic film seedling nursery using a late maturity japonica cultivar Wuyunjing 3. The seedlings of three different ages were transplanted into paddy field, and yield and yield components were tested. The main results were as follows: (1) The effect of seedling age on seedling quality and yield was predominant, and followed by fertilizer amount and sowing density. (2) The trend of grain yield reduction was obvious when seedling age was extended from 16 d to 21 d after sowing, although under dense sowing with less fertilizer application (treatments code M1 and M2), or thin sowing with more fertilizing (code X3). Therefore, transplanting at optimum seedling age is very important for mechanical transplanting. (3) The seedling quality indices, such as root-developing ability and sugar content in stem and sheath at seedling age of 21 d were superior to that at seedling age of 16 d (significantly different), but the grain yield in paddy field of 21 d seedling age was decreased because of plant and panicle number reduction. So the indices of vigorous seedling would be varied with seedling age. (4) Path analysis of yield components on yield showed that panicle number was most effective (path coefficient 1.1112) followed by grains per panicle (path coefficient 0.6517) for mechanical transplanting rice.

Effect of Irrigation Times on the Photosynthetic Charcteristics of Flag Leaf and Grain Yield in Wheat Hybrid Ji’ai 1/ C6-38

ZHANG Yong-Li;XIAO Kai and LI Yan-Ming

Acta Agron Sin. 2006, 32(03):  410-414. 

Abstract ( 1870 )   PDF (332KB) ( 906 )   Save

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A field experiment with three treatments of different irrigation times at different stage was conducted during wheat growing period. The results showed that with the increase of irrigation times, the net photosynthetic rate (P_n), chlorophyll concentration (Chl), soluble protein contents (Pr), stomatal gas conductance (g_s), mesophyll gas conductance (g_m), relative steady phase of chlorophyll content(RSP), photosynthetic active duration(PAD) and leaf source capacity(LSC) of flag leaf were increased in wheat hybrid and its parents, and the grain yield and yield components in creased also. The P_n, Chl, Pr, g_s and g_m of flag leaf in hybrid were more sensitive to the times of irrigation than that in its parents at different stages after flag leaf was fully expanded. The heterosis from mid-parent(H_m) of all above traits were increased with the increase of the irrigation times.

Effects of Water Supply Levels in Different Growth Stages on Maize Yield under Different Fertilizer Levels

GAO Ya-Jun; LI Sheng-Xiu; TIAN Xiao-Hong; LI Shi-Qing; WANG Zhao-Hui and DU Jian-Jun

Acta Agron Sin. 2006, 32(03):  415-422. 

Abstract ( 1916 )   PDF (608KB) ( 1141 )   Save

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Maize growth and yield are sensitive to soil water. However, the effects are related to maize growth stages. Fertilizers supply may influence the effect of soil water in different growth stage on maize yield, but few report focus on it.
The pot experiment and field experiment were conducted in the southern Loess Plateau. The purpose was to investigate effects of water supply levels in different growth stages on maize yield under different fertilizer levels. The pot experiment concerned soil water content in seedling stage, internode elongation stage, tasselling stage, filling stage and fertilizer levels. Soil water content included five levels (45%, 60%, 75%, 90% and 105% of field capacity) while fertilizer included normal fertilizer level (NL: 0.4 g N·kg^-1 dry soil+ 0.2 g P₂O₅·kg^-1 dry soil) and low fertilizer level (LL: 0.2 g N·kg^-1 dry soil+ 0 g P₂O₅·kg^-1 dry soil). The field experiment concerned irrigation in seedling stage (X₁), internode elongation stage (X₂), tasselling stage (X₃), filling stage (X₄) and N fertilizer rates (X₅). Irrigation water included five levels (0, 25, 50, 75 and 100 mm), and N fertilizer application also included five levels (0, 112.5, 225, 337.5 and 450 N kg/ha).
Maize yield of LL was significantly less than that of NL whatever soil water content was. Maize yield of NL was increased continuously with the increase of soil water content in the range of 45%–105%. However, the yield of LL was increased with the increase of soil water content and reduced when soil water content was more than 90% in seedling stage, tasselling stage and filling stage. In internode elongation stage, the yield both of LL and NL were increased continuously with the increase of soil water content in the range of 45%–105%. In all the stages, maize yields under soil water content of 45% or 60% were lower, compared with that of 75% (control). The yield reduction of NL was less than that of LL. Yield of the treatment with soil water content 45% and 60% in tasselling stage was less than that in other stages whatever fertilizer was, and that in seedling stage was more than that in tasselling stage but less than that in other stages.
Maize biomass of LL was significantly less than that of NL despite of soil water content. In all stages, biomass of LL and NL were increased continuously with the increase of soil water content in the range of 45%–105%. For LL and NL, the biomass of the treatment with soil water content of 45% and 60% in tasselling stage was less than that in other stages, and that in internode elongation stage was more than that in tasselling stage but less than that in other stages. Biomass of LL and NL was greater under soil water content of 90% and 105% than that of control in all stages.
Two regression models were set up according to data of the field experiment, describing the relationship of maize yield (Ygrain) or biomass (Ybiomass) and irrigation water in seedling stage (X1), internode elongation stage (X₂), tasselling stage (X₃), filling stage (X₄) and N rate (X₅).
Y_grain =12473.4+278.6X₂+585.4 X₅－427.4X₄X₅;
Y_biomass = 24321.8 + 224.2X₂ + 315.2X₃ + 1346.3X₅－280.1X₁²－468.3X₂²－198.2X₃²－232.7X₄²－437.0X₁X₂－
238.6X₂X₃－601.9X₄X₅
The results indicated that soil drought in all stages of maize growth resulted in the reduction of maize yield. However, the yield reduction was decreased by sufficient fertilizer supply, especially under severe drought. Maize yield was quite sensitive to water in tasselling stage, whatever fertilizers were applied. So it was very important for maize to avoid water stress during growing period. Internode elongation stage was another key stage sensitive to soil water in dryland. The increase of soil water content in the stage had more significant effect on maize yield when fertilizer was shortage. Drought in seedling stage also caused significant decrease of maize grain yield, especially when fertilizer was not sufficient. Maize yield was increased with the increase of relatively soil water content in the range of 45% to 90%, but which was changed by fertilizer supply and different stages of maize growth. The increase of maize yield was contributed more by fertilizer than by water. The effect of water on maize yield was also limited when fertilizer was shortage. In the present situation, more fertilizer supply is the main way to increase crop yield in the Loess Plateau.

Effects of High Temperature during Grain Filling on Key Enzymes Involved in Starch Synthesis in Two Wheat Cultivars with Different Quality Types

ZHAO Hui;DAI Ting-Bo;JING Qi;JIANG Dong;CAO Wei-Xing;LU Wei and TIAN Xiao-Wei

Acta Agron Sin. 2006, 32(03):  423-429. 

Abstract ( 1840 )   PDF (518KB) ( 1003 )   Save

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High temperature is a key factor during wheat grain filling affecting grain yield and quality in main production areas of China, but the physiological mechanism of quality formation related to high temperature stress remains unclear. The experiments were carried out in growth chambers to investigate the effects of high temperature conditions during grain filling on the formation of total starch, amylopectin and amylose, and the activities related to starch synthesis using two wheat cultivars including Yangmai 9 with low grain protein content and Xuzhou 26 with high grain protein content. Four day/night temperature regimes of 34℃/22℃, 32℃/24℃, 26℃/14℃ and 24℃/16℃ from 7 days after anthesis until maturity were established, which included two daily average temperatures 28℃ and 20℃, and two day-night temperature differences 12℃and 8℃. The results showed that the contents of total starch and amylopectin were markedly reduced, but amylose content was slightly affected (Fig.1, Fig.2, Fig.3 and Table 1), and the ratio of amylopectin to amylose was reduced significantly in higher temperature treatments. During the early period of grain filling, the activities of key enzymes such as sucrose synthase (SS) and granule-bound starch synthase (GBSS) were enhanced, but the activities of SS, GBSS and soluble starch synthase (SSS) during the late period of grain filling were decreased in high temperature treatments (Fig.4, 6, 7). GBSS activity was increased in Yangmai 9, and SSS activity was decreased in Xuzhou26 during early period of grain filling under high temperatures (Fig. 6,7), indicating the different enzymology mechanism in two wheat cultivars. In addition, under high temperatures, grain starch content was similar between two treatments with day-night temperature differences in two wheat cultivars. Under optimum temperatures, grain starch content was higher in the treatment of 26℃/14℃(Fig. 1). Moreover, under high temperatures, SS activity was higher in the treatment of 34℃/22℃ during the middle and late period of grain filling, whereas the activities of SSS and GBSS were higher under 32℃/24℃ (Fig. 4, 6, 7). Under optimum temperatures, the activities of three key enzymes were higher in the treatment with higher day-night temperature difference (26℃/14℃). The above results indicated that starch synthesis was affected more by temperature levels than by day-night temperature differences.

Estimation of Nitrogen Content and C/N in Rice Leaves and Plant with Canopy Reflectance Spectra

XUE Li-Hong;YANG Lin-Zhang and FAN Xiao-Hui

Acta Agron Sin. 2006, 32(03):  430-435. 

Abstract ( 2048 )   PDF (535KB) ( 1315 )   Save

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Carbon (C), nitrogen (N) metabolism provides the substance basis of plant growth and development, and non-destructive, quick assessments of C, N content (%) and C/N with remote sensing are very necessary for the research of plant growth regulation, carbon and nitrogen cycling, and global climate change. In order to study the feasibility of the C, N content and C/N measurements with canopy reflectance spectra, canopy spectral reflectance (460–1 650 nm) data at tillering, heading and filling stage of rice (Oryza sativa L.) in field experiments with different N levels at two different sites were recorded with MSR-16 radiometer, and corresponding C, N content and C/N were also measured. Then the relation of C, N content and C/N in leaves and plant to reflectance of single band and all two-band combinations in the ratio vegetation index (RVI, λ₁/λ₂), normalized difference vegetation index NDVI (λ₁－λ₂)/(λ₁+λ₂), and difference vegetation index (DVI, λ₁－λ₂) were analyzed. Results showed that strong correlation existed between C, N contents and C/N in rice leaves/plant and spectral vegetation indices, the performance of RVIs was consistent with NDVIs, while a little difference with DVIs. Correlogram of C/N to different spectral vegetation indices was similar with that of N (Fig.2). Ratio and normalized difference vegetation index composed by 510 nm and 460 nm was significantly correlated with N content in leaves and plant, and data from three different development stages can be fitted with an uniform equation (Fig.3). While the relationship of C/N and vegetation indices at post-heading (including heading stage and filling stage) was better than that at whole growing stage, with the best index of ND(1650,710). Tests with other independent dataset showed that the estimation precision of N content and C/N in leaves and plant was 80.51%, 81.09%, 76.36% and 70.70%, with the RMSE of 0.20, 0.26, 1.64 and 3.95 respectively (Fig.4). This suggests that vegetation indices can be used to estimate N content and C/N in rice.

Effect of Sulphur Fertilizer on Photosynthesis Characteristics and Grain Yield of Two Winter Wheat(Triticum aestivum L. )Cultivars with Different Spike Types

ZHU Yun-Ji; XIE Ying-Xin; GUO Tian-Cai; MA Dong-Yun; DAI Ting-Bo and CAO Wei-Xing

Acta Agron Sin. 2006, 32(03):  436-441. 

Abstract ( 1910 )   PDF (475KB) ( 1002 )   Save

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Sulphur(S) is an essential nutrient required for all living organism. Over the last two decades, many regions in the world have a fundamental shift in the S balance toward deficit in agricultural systems for several reasons. High analysis N and P fertilizers have gradually replaced traditional ones that contain S. In addition, yields of agricultural crops have increased markedly, and in some cases more than doubled, resulting in increased removal of nutrients, including S from soils, and so on. Although wheat has a relatively low requirement for S, deficiency of S in wheat growth has been observed in many regions in China. Apart form the clear effects on crop growth and grain yield, crop S nutrition can also exert a large influence on the quality of wheat. Previous studies focused on effects of S fertilizer on leaf net photosynthesis (Pn) and yield of wheat. This paper aims to compare the effects of different S fertilizer treatments on leaf photosynthesis characteristics and grain yield of both multi-spike（Yumai 49）and large-spike（Yumai 66）wheat cultivars. The results would help characterize the photosynthetic mechanism for changed grain yield under sulphur application and improve fertilizer strategy in modern wheat production systems in China. Experiment was conducted with soil available sulphur content of 15.8 mg.kg^-1 in 2001/2002 and 2002/2003 growing seasons. A total of eight fertilization treatments were implemented, i.e. no S fertilizer(C1S0,C2S0), 60 kg.ha^-1 S for base application(C1SI,C2S1), 120 kg.ha^-1 S for base application (C1S2,C2S2) and 60 kg.ha^-1 S for base application and topdressing at Jointing stage in 5:5 ratio(C1S3,C2S3). The results indicated that comparing with S0, photosynthesis traits of all the treatments with sulphur fertilizer were increased. Canopy apparent photosynthesis (CAP) and flag leaf’s chlorophyll (Chl) content with the treatment of sulphur application of both the cultivars were obvious higher than their respective control in filling stage(Fig.1, Fig.3), meanwhile flag leaf net photosynthesis (P_n) was significantly increased, and exhibited slower decline at the late grain filling stage（Fig.2）. The increasing of flag leaf transpiration (T_r) expressed strong potential of physiological metabolism of treatments with sulphur fertilizer(Fig.4). There was the same trend in the change of leaf photosynthesis characteristics in both cultivars and Yumai 66 showed obvious dominance in CAP and Pn in filling stage. The grain yields in treatments of sulphur application were higher than those in no sulphur fertilizer , and S3 of Yumai 49 and S1 and S3 of Yumai 66 were significantly different from the control at the 0.01 probability level（Table 1 and 2）,which resulted from increasing 1000-kernel weight and No. of spikes respectively. The treatment of 60 kg.ha^-1 sulphur for base application and topdressing at Jointing stage in 5∶5 ratio showed the best effects. With treatment of no S and 120 kg.ha^-1 S for base application, CAP, P_n, Tr and Chl content were lower ,which resulted probably from the unbalanced nutrients in soil due to the improper input of nutrients which were responsible for the fast declining of flag leaf and canopy photosynthesis characteristics during grain filling. Some suggestions of sulphur fertilizer rational application were also put forward in winter wheat cultivation.

Modeling Fiber Quality Formation in Cotton

MA Fu-Yu; ZHU Yan; CAO Wei-Xing; YANG Jian-Rong; ZHENG Zhong; CHEN Hai-Tong and MU Cai-Yun

Acta Agron Sin. 2006, 32(03):  442-448. 

Abstract ( 1819 )   PDF (522KB) ( 984 )   Save

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Accurate prediction of fiber quality formation is highly important for successful cotton growth simulation and management decision. Experiments were conducted in natural environment to quantitatively describe the relation between the dynamic process of fiber quality formation and conditions of water supply and growth temperature in Nanjing (32°03′N，118°47′E), Anyang（36°7′N, 116°22′E）, Baoding (39°05′N, 115°47′E) and Shihezi (44°26′N，86°01′E) in 2002 and in Shihezi only in 1997，2003. A simulation model for predicting fiber elongation, strength and cellulose content accumulation was developed based on days after anthesis (DAA) and boll physiological development time (BPDT). The effects of soil water content, daily mean temperature (DMT) and daily temperature difference (DTD) were taken into account, along with genetic parameters for different cultivars in the model. The model was validated using the experiment data sets under different conditions of DTD, DMT, and soil water status at different eco-sites. The root mean square errors (RMSEs) between the simulated and observed values of fiber length, fiber strength and cellulose content are 1.15 mm, 1.03 cN·tex^-1 and 4.37%, respectively, indicating that the model is accurate and applicable under different conditions.

SCAR Markers and Preliminary Gene Mapping of a Dominant Semi-dwarf Mutant in Rice

LIU Bin-Mei; WU Yue-Jin; TONG Ji-Ping; WU Jin-De; YU Zeng-Liang; ZHANG Ying and CHENG Can

Acta Agron Sin. 2006, 32(03):  449-454. 

Abstract ( 1877 )   PDF (1936KB) ( 1128 )   Save

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Utilization of dwarf and semi-dwarf genes was one of the greatest achievements in rice breeding in 20^th century. Through ion beam mutagenesis, a new rice semi-dwarf mutant Y98149 was obtained. The plant height of Y98149 was controlled by a pair of dominant genes, not affected by cytoplasm. This dominant semi-dwarf gene could be used to resolve the problem of the dwarf gene deficient in rice dwarf breeding and the heterobeltiosis of F₁ in plant height in the utilization of inter-subspecific heterosis. Y98148 and Y98149 are near-isogenic lines(NILs) of dominant semi-dwarf gene. A RAPD analysis was made between NILs with arbitrary 10-mer oligonucleotide primers and three polymorphic RAPD bands were obtained. The three special RAPD bands were recovered ,purified and inserted in pUCm-T vector, and then transferred into E.coli. JM109. Positive colonies were identified for sequencing(Fig.1). According to the obtained sequences, 18–24-mer specific primers were designed as SCAR primers, and the SCAR-PCR reaction conditions were optimized. Consequently, RAPD markers S1041₅₂₅, S1076₅₄₉ and S1272₄₀₃ were successfully converted into SCAR markers SCS1041₄₉₈, SCS1076₅₁₀ and SCS1272₃₈₈, most optimal annealing temperature were 61℃,58℃ and 62℃,respectively. F₂ progeny with 384 individuals of Y98148×Y98149 was analyzed to map SCAR markers in relationship to this gene. The result indicated that the genetic distances of SCS1041₄₉₈, SCS1076₅₁₀ and SCS1272₃₈₈ to the gene were 12.6 cM, 7.5 cM and 16.3 cM, respectively. The blast result indicated nucleotide sequence of marker S1272₄₀₃ was 99% identical with the BAC clones B1249D05（AP006451）and OJ1212_C12（AP005604）on chromosome 7 and was a single copy in rice genomic DNA. B1249D05 and OJ1212_C12 had a overlap of 23 kb, which marker S1272₄₀₃ lay in. So this new semi-dwarf gene was considered to be located on chromosome 7 preliminarily. The markers are useful to marker-assisted selection for the breeding and tagging it with positional cloning.

REVIEW

Perspectives of Molecular Design Breeding in Crops

WAN Jian-Min

Acta Agron Sin. 2006, 32(03):  455-462. 

Abstract ( 2124 )   PDF (772KB) ( 1620 )   Save

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Breeding and extension of new cultivars with good qualities, multiple resistances, stress tolerances, and high yielding are essential to fulfill the food safety in China. However, most crop breeding activities are still based on visual and phenotypic selection, where the breeder’s experience plays a major role, and the breeding efficiency is extremely low. On the other hand, a large amount of biological data keeps accumulating dramatically as the rapid development in biotechnology and genomics. But the breeders have no ideas how to integrate this information in their traditional breeding programs due to the lack of appropriate tools and methods. Molecular design breeding first studies the dynamitic behaviors from multiple levels among all components consisting of a plant, and their interactions with environments during development. And then a blueprint of specific cultivars meeting particular breeding objectives is designed, and the optimum strategy to reach the blueprint is provided. Therefore, by understanding the genetic basis of all agronomically important traits and the allelic variation at those loci, the breeders would be able to design superior genotypes at their requirements ‘in silico’. By design breeding, the crossing and selection process can be simulated and optimized before going to the field, and thus the breeding efficiency can be greatly enhanced by shifting the tradition experience breeding to the precision breeding.

RESEARCH NOTES

Factors Affecting Seeding Emergence in Winter Wheat under Different Tillage Patterns with Maize Stalk Mulching Returned to the Field

LI Shao-Kun; WANG Ke-Ru; FENG Ju-Kai; XIE Rei-Zhi and GAO Shi-Ju

Acta Agron Sin. 2006, 32(03):  463-465. 

Abstract ( 2090 )   PDF (333KB) ( 1166 )   Save

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The present study was to make clear the reasons affecting the emergence of winter wheat seedling in maize stalk mulching fields in North China Plain. The results indicated that the wheat seedling rates under all treatments of stalk return field declined compared with the traditional tillage pattern (ploughed before sowing, but no stalk mulching). The main five reasons are sorted as sowing too shallow, sowing to deep, physical obstacles by maize stalks, seed moldiness and deficiency or unevenness of soil water, and their priority orders in different tillage patterns were different. The relationships between weight of maize stalk return field (y) and number of wheat seedling (x) could be simulated by power functions y= 4.206x^－7192 (mulched with whole stalks and un-ploughed and y= 509.4x^－0597 (mulched with crushed stalks and un-ploughed).

Effects of Uniconazole on Nitrogen Distribution and Grain Protein in Late Growing Stage of Wheat with Different Planting Densities

HAN Hui-Fang; YANG Wen-Yu; LI Zeng-Jia and GUAN Hua

Acta Agron Sin. 2006, 32(03):  466-468. 

Abstract ( 1939 )   PDF (256KB) ( 927 )   Save

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The experiment was conducted with seed dressing of uniconazole (S-3307) with different concentrations (0, 10, 20 and 40 mg/kg) and different planting densities(90×10⁴,180×10⁴ and 270×104/ha) in late growing stage of wheat Mianyang 26（cv）. The results showed that the contents of nitrogen accumulated in ear, culm and leaf were more in S-3307 treatments than in control, and the effect of S-3307 on main stem was bigger than that on tiller. The grain protein was significantly higher in S-3307 treatments than in control. With the increase of S-3307 concentration, the contents of albumin and globulin were significantly increased, which the effect of 20 mg/kg S-3307 (B3) was the best, and the contents of gliadin and glutenin also increased. It suggested that the grain protein is regulated through nitrogen source regulation by S-3307.

Inheritance of Pollen Fertility in Progenies of an Indica-japonica Hybrid Rice, IR36/Kamairazu

LÜ Chuan-Gen; GAO Yan-Hong; ZONG Shou-Yu and ZOU Jiang-Shi

Acta Agron Sin. 2006, 32(03):  469-471. 

Abstract ( 1867 )   PDF (278KB) ( 882 )   Save

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To understand inheritance of pollen fertility in progenies of indica-japonica hybrid rice, the present study tested pollen fertility of 47 indica-japonica F₁ and tracked that in progenies of a representative hybrid, IR36/Kamairazu (KM). The 47 hybrids had an averaged pollen fertility of (79.9±31.2)%, and 68% of them showed partial pollen sterility by their fertility lower than 90%. The pollen fertility of IR36/KM F₁ was 79.5%, its derived F₂ plants have a higher averaged fertility as (91.0±15.7)% (Fig.1). A plant A4-3, which was from F₂ population and have pollen fertility of 98.3%, showed averaged fertility of (95.9±11.1)% in its derived F₃ population including 81 plants. While, a plant A4-6, which has pollen fertility of 61%, showed a significant lower averaged fertility of (74.3±35.2)% in its derived population including 51 plants (Fig.1). Two plants which were in F₃ population derived from A4-3 and have pollen fertility of 99.2% and 99.5%, derived populations of fertility as (93.0±7.4)% and (94.9±3.5)%, respectively. While, two plants, both of which have pollen fertility of 69.2%, derived populations of fertility as (88.5±22.1)% and (89.8±6.7)% (Table 1). The results implied that, pollen fertility of IR36/KM was controlled by multigene, and showed conform to the allelic interaction model. In the F₂, two F₃ and four F₄ populations, there were no significant correlation between pollen fertility and spikelet fertilized rate in populations which have higher averaged pollen fertility, while, showed significant correlation in populations which have lower averaged pollen fertility (Table 2).

Identification of Indica-japonica Character and Analysis on the Yield Combination Ability for the New Germplasm Yihui 1577

BAO Ling-Feng; LIN Gang; ZHAO De-Ming; LI Yun-Wu; ZENG Jian and HE Bin

Acta Agron Sin. 2006, 32(03):  472-474. 

Abstract ( 1937 )   PDF (266KB) ( 971 )   Save

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The indica-japonica characteristics of a novel Rice germplasm Yihui 1577 was identified based on six agronomic traits of lemma hair, pheno reaction, internode length between the first and second nachiees, the hull color at heading, leaf hair and grain shape with the morphological index method founded by Mr Chen. The result showed that Yihui 1577 belong to japonicalinous restorer line. The yield combination ability analysis of Yihui 1577 made by not complete dual crossing with 4 CMS lines and 6 restore lines indicated that general combination ability effect value of Yihui 1577 was 0.226 and that of Minghui 63 was –0.113, the former was superior to the latter.