Abstract:

Foxtail millet [Setaria italica (L.) Beauv.] is a kind of millet crops, its genetic research is relatively laggard as compared with other cereals such as maize, rice and wheat. Chromosome gene location analyses of agronomical important traits are rarely reported. Some basic knowledge about genes controlling important characteristics are important to improve breeding program. Our research group established a complete set of primary trisomic of foxtail millet in 1993, and began to conduct chromosome gene location by using the system in 1994. So far, we have identified that the waxy endosperm gene is located on chromosome 4, dwarf gene of An’ai 3 on chromosome 3, red glume gene and bristle gene on chromosome 1 and 2, the male-sterile gene of line 1066A and yellow seedling gene on chromosome 6 and 7 respectively. This research still conducted the chromosome gene location of foxtail millet by trisomic analysis. Crosses were made by using Yugu 1 primary trisomic series 1–7 and tetrasomics 8, 9 as female parents, dominant dwarf, Fagu 56-81 and Maqingmiao as male parents, so as to identify the locations of dominant dwarf gene, white millet gene and grey millet gene. Each F₁ plant was identified according to plant morphological characteristics of primary trisomic series 1–7 and labeling traits of male parent; the trisomics 8, 9 of F₁ plants were identified by checking chromosome number of plant root tip cells. Through investigating and analyzing the segregation of F₂ populations, the dominant dwarf gene was located on chromosome 3, white millet gene on chromosome 4, grey millet gene on chromosome 6. Allelic test for 9 grey foxtail millet varieties obtained from different regions showed that these grey millet lins are all allele. Gene linkage analysis were carried out by using the segregating populations derived from cross combinations of 1066A×Fagu56-81 and 1066A×Maqingmiaoto. As a result, the exchange value between the waxy endosperm gene and white millet gene on chromosome 4 was (28.9±4.4) cM; and the exchange value between the sterile gene of 1066A and cyan-millet on chromosome 6 was (23.2±1.8) cM.

Key words: Foxtail millet, Chromosome location, Linkage analysis, Allelision test