Studies On The Genetic Rule For The Al-type Male Sterility In Wheat

In order to acquire the resources of the three-line transferred in Xinjiang of genetic rule and discuss the AL-type fertility restoration gene number of male sterility line and action mode, heterosis and cytoplasmic effect. In this study, sterile line AL18A , maintainer line 18B and the restorer 99AR144-1 were selected, the corresponding hybrid and backcross combinations were prepared, segregation analysis method using Mendelian inheritance and major gene plus polygene multi-joint quantitative character segregation analysis to study the main yield and agronomic traits. The results are as following:1. Mendelian inheritance segregation analysis results showed that: (1) the(AL18A×99AR144-1)F₁ bagged seed-setting percent above 81%, the restores gene was the dominant heredity. (2) the sterile division standard by 0 achievement, the ratios of fertile to sterile in the F₂ populations were 15:1 and the ratios in the A/F₁ were 3:1 by plant fertility segregation analysis. With Chi-square test, two pairs of restoring genes had superposition and accumulation effect. (3) the fertility segregation in the F₁/B populations deviated obviously from 3:1, we concluded that the genetic of restoring gene by means female gamete was abnormal under AL-type cytoplasm background.2. On P₁, P₂, F₁, B₁, B₂ and F₂ generations of multi-joint quantitative character segregation analysis resulted show that:(1)the combination of fertility restoration accorded with two major additive- dominance-epistatic genes, of which additive effect were taken as main genetic factor and the additive effect is equal. (2)two pairs major genes for fertility restoration showed partial dominance. (3)the interactions between two pairs major genes, additive×additive epistatic effect was the leading effect, the additive-dominance-epistatic effects of multiple genes were also existence. (4)the heritability of major genes is 46.54%, 96.27% and 93.49% in B₁, B₂ and F₂ populations, the heritability of polygenes is 0, 1.31% and 2.53%,respectively.The higher heritability of major genes was beneficial to breeding of restorer lines.3. On plant height, spike length and grain weight per spike of multi-joint quantitative character segregation analysis resulted show that:(1) they were controlled by 1 pair major genes plus polygenes. (2) the heritability of major genes of plant height and spike length in the B₂ and F₂ generations, B₁ and F₂ generations were predominant; grain weight per spike based on the heritability of polygenes.4. Heterosis and cytoplasmic effect analysis showed that: (1) three types of AL18A×99AR144-1 heterosis analysis showed that F₁ generation of plant height, effective panicle number, 1000-grain weight, grain weight and biological yield had positive heterosis, grain weight and grains per spike, number of grains per gram of straw had mainly negative heterosis. (2) the heterosis had the recession obviously in F₂, the average decline rate of descending order as following: grain yield>grain weight per spike>biological yield>grains per spike>effective panicle number>spike length>plant height>G/W>1000-grain weight. (3) the combinations of homonuclears-alloplasm AL18A×99AR144-1 compared with 18B×99AR144-1, which indicated that sterile cytoplasm of AL18A generally no adverse effects on yield.