Molecular Detection And Genetic Effects Analysis Of Genes For Some Important Traits In Wheat (Triticum Aestivum L.)

Wheat is one of the most important food crops in China.The excellent wheat varieties guarantee the high-quality and high-yield production.So far,with the development of modern molecular biology technology,molecular design breeding of wheat varieties has been established and developed.The molecular design of wheat varieties requires full analysis of the genetic basis of the parent materials to obtain specific molecular markers that relate to target traits.In recent years,with the development of modern biological techniques and methods,some important genetic basis of wheat has been analyzed,and the specific molecular markers of related genes have been developed.Moreover,crucial genes have been cloned.The detection of breeding parents using the specific molecular markers of important wheat genes plays an important role in fully understanding the genetic information of breeding parents.It is also basic for the molecular marker-assisted selection of breeding parents and hybrids.Therefore,we reviewed a large number of related literature and selected molecular markers for genes related to wheat quality,early maturity,plant height,kernel weight and disease resistance.A detection of specific molecular markers for important genes and agronomic traits were tested on 202 wheat materials.Additionally,the genetic effects of related genes were analyzed.The main results are described as follows.1.Molecular detection of stripe rust resistance genes showed that,out of 202 materials,63 cultivars carry Yr9 gene;six cultivars carry Yr17 gene,and 135 cultivars carry Yr26 gene.There is no reliable molecular markers for detecting Yr5.Neither Yr15 nor Yr18 was detected in the tested materials,and the reliability of molecular markers for Yr10 needs to be further verified.The feature of adult plant resistance to stripe rust showed that,among the tested materials,118(accounting for 71.95%)cultivars were resistant and the rAUDPC values ranged from 2.83% to 35.96%,while the rest 46(accounting for 28.05%)cultivars were sensitive and the r AUDPC values ranged from 30.30% to 90.00%.Specially,27 cultivars showed immunity,and the rAUDPC ranged from 2.83% to 19.86%.The ratio of plant resistance to stripe rust in high-generation materials and imported materials was higher than that of parent materials.2.In this study,202 wheat materials were detected by using the specific molecular markers of wheat dwarf genes.10.89% of materials contained Rht-B1 b,73.76% and 65.84% contained Rht-D1 b and Rht8,respectively,6.93% contained none of the three dwarf genes.Furthermore,12 materials contained both Rht-B1 b and Rht8,while 104 materials contained Rht-D1 b or Rht8.The analysis of genetic effect showed that three dwarf genes and their combinations had differently significant effect on reducing wheat height,ranking as RhtD1b>Rht-B1b>Rht8,and Rht-D1b+Rht8>Rht-D1b>Rht-B1b+Rht8>Rht-B1b>Rht8.The dwarf genes didn't significantly affect the effective tiller,ear length,spikelet number and grains per spike.However,thousand-kernal weight could be increased by Rht8,which had some advantages among dwarf genes.3.The detection of vernalization genes showed that the frequencies of dominant alleles at the Vrn-B1 locus and Vrn-D1 locus are 13.86% and 50.00%,respectively.Additionally,wheat cultivars containing both Vrn-B1 and Vrn-D1 alleles were discovered,while no material containing the Vrn-A1 or Vrn-B3 genes was found.In the tested materials,most wheat cultivars carry the gene Ppd-D1 a.The vernalization genes could effectively shorten the heading date of wheat and improve its ecological adaptability.Wheat varieties(lines)containing Vrn-A1 or Vrn-B3 are suggested to be introduced in China to enrich the gene bank of early maturing genes in wheat.4.The detection of specific markers showed that about 8% of cultivars carry 1Dx5+1Dy10 genes,which increase sedimentation value,the development and stability time of dough.Though 1Dx5+1Dy10 could significantly improve wheat quality traits,it had a negative effect on ear length,the number of spikelets and grains per spike.5.Among the tested materials,only 19.31% carried TaCwi-A1 a allele,while 42.57% carried TaSUS2-2B-H allele and 11.39% carried both two alleles.The TaSUS2-2B-H allele could increase the number of wheat spikelets,while both TaCwi-A1 a gene and TaSUS2-2B-H gene significantly increased kernel width,grain diameter,and 1000-grain weight of wheat.