Genetic Analysis In Photoperiod-thermo Sensitive Male Sterile Wheat

The discovery of photoperiod-temperature sensitive male sterile(PTSM) wheat established the new way to utilize heterosis of wheat.Since the PTSM wheat was a typical ecological sensitive genetic phenomenon,it was controlled not only by male sterile genes but also regulated by ecological factors,such as photo-period and temperature,which leaded to its genetic mechanism being difficult.So that, strengthening the research of genetic mechanism and definiting the means of sterile genes controlling in photoperiod -temperature sensitive male sterile wheat,in order to provide important theoretical bases for the breeding and identification of PTSM as well as fully utilizing heterosis in two-linear hybrid wheat.The PTSM line was core material of two-line system in hybrid wheat breeding. To research the genetic mechanism of PTSM wheat,the PTSM wheat BS20,BS210,BS366,BS400,BS1999,BS709,BS93 as parents,several F₂ populations derived from cross among the seven parents were studied,applying mixed in heritance model which derived from single segregating generation and multiple generations.The results are shown as follow:1.The genetic distance cluster of seven PTSM lines(BS20,BS210,BS366,BS400,BS1999,BS709 and BS93) were analyzed.The genetic distance between BS210 and other lines was the largest,the values of genetic distance were between 0.78 and 0.85. The values were between 0.38 and 0.51 secondly,the values were between 0.29 and 0.36 were the smallest.2.The 13 F₁ population derived from 7 PTSM lines were studied.The resultes showed that the inbred combination show high fertility in F1 population would show the greater separation of fertility and smaller effect of allele in F2 population than other inbred combination.Based on these resultes,the conclusion was preliminarily deduced that the major genes control male sterility of BS709 and BS366,13S20 and BS400,BS20 and BS366 are share same alleles,but BS210 and BS93 are not the same alleles.3.Two F₂ populations derived from cross BS210×BS20 and reciprocal cross BS20×BS210 were investigated by the mixed major gene plus poly-genes in genetic model of quantitative traits.The resultes showed that cross BS210×BS20 was controlled by two additive-dominance major genes and additive-dominance polygenes (E-2),reciprocal cross BS20×BS210 was controlled by two additive-dominance-epistatic major genes and additive-dominance-epistatic polygenes(E-0).The genetics of major genes in cross BS210×BS20 is additive-dominance,in reciprocal cross BS20×BS210 is additive mainly and epistatic effect is negatively.The heritabilitis of major genes were 36.71%and 40.285%.The genetics of poly-genes in the two crosses are dominance and additive,the heritabilitis of poly-genes is little.Those indicated that the effects of major genes were identical approximately but the effects of poly-genes were great different.The heritabilitis of major genes is higher than poly-genes.The effect of environment was significant to fertility,the variance of environment were 49.98%and 40.785%in above two crosses,which is almost equal to or even over than variance of major genes.4.Three F₂ populations derived from cross the same female parent and different male parents(BS210×BS20,BS210×BS400,BS210×BS1999) in the same ecological environment were studied by the mixed major gene plus poly-genes in genetic model of quantitative traits.The genetic models were different incompletely,which were controlled by two additive-dominance major genes and additive-dominance polygenes (E-2),E-2,two additive-dominance-epistatic major genes and additive-dominance polygenes(E-1).The genetics of major genes in the three crosses were predominant on additive effect,the heritabilitis of major genes are 44.09%,30.32%,26.37%. Additive effects of poly-genes were 4.969,22.058,14.861,the heritabilitis of polygenes were 11.32%,14.63%,13.39%.The effects of major genes and poly-genes were identical approximately in the three crosses.The heritabilitis of major genes is higher than poly-genes.The effect of environment was significant to fertility,the variance of environment were 48.59%,55.05%,60.24%in above three crosses.5.Three F₂ populations derived from cross the same male parent and different female parents(BS210×BS1999,BS20×BS1999,BS400×BS1999) in the same ecological environment were studied by the mixed major gene plus poly-genes in genetic model of quantitative traits.The three crosses were controlled by two additive-dominance -epistatic major genes and additive-dominance polygenes(E-1).The genetics of major genes in the three crosses were predominant on additive and dominance effect,the heritabilitis of major genes are 26.37%,29.59%,31.63%.The effects of additive and dominance were equal,the heritabilitis of polygenes were 13.39%,12.62%,14.26%.Those indicated that the effects of major genes and polygenes were different in the three crosses.The heritabilitis of major genes is higher than poly-genes.The effect of environment was significant to fertility,the variance of environment were 60.24%,57.79%,54.11%in above three crosses.6.F₂ population derived from cross BS210×BS20 cultivated in the same location twoyears was studies by the mixed major gene plus poly-genes in genetic model of quantitative traits.Those were controlled by two additive-dominance major genes and additive-dominance polygenes(E-2).The genetic effects were equal approximately in two years,but the heritabilitis of genes and effect of environment were not equal.The variance of environment was greater in 2006～2007 than that in 2007～2008.7.Eight F₂ populations were controlled by two major genes and polygenes(Emodel), the heritabilitis of major genes is higher than poly-genes,the effect of environment was significant to fertility.Those indicated that the fertility was controlled by both of inheritable factor and environmental factor,impacted by the effect of poly-genes modifying as well.In a word,the photoperiod-temperature sensitive male sterility was called Environment Sensitive Male Sterile.