Distribution Of Vernalization And Photoperiod Genes In Jiangsu Wheat Cultivars And Their Effects On Agronomic Traits

Vernalization gene and photoperiod gene are important genetic factors controlling wheat growth and development.Wheat with different vernalization photoperiod genotypes shows different environmental adaptability.In recent years,the postponement of wheat sowing date and the occasional extreme climate in Jiangsu have all posed a threat to the high and stable yield of wheat in Jiangsu.Studies on the recessive components of vernalization and photoperiod genes and their correlation with wheat growth and development traits are helpful to cultivate varieties with excellent traits and stable development.Therefore,this paper mainly carried out the following two aspects of research:(1)Taking 114 wheat varieties(lines)planted in Jiangsu Province from 1940 to 2016 as materials,STS molecular markers of vernalization genes Vrn-A1,Vrn-B1,Vrn-D1,Vrn-B3 and photoperiod genes Ppd-A1,Ppd-B1 and Ppd-D1 were used to detect these varieties and analyze the distribution of vernalization and photoperiod genes in different regions and ages.(2)73 varieties of barley in different regions of the country were used as materials to detect their vernalization and photoperiod genotypes,and early sowing,suitable sowing and late sowing were carried out to simulate extreme climate,and the correlation between vernalization and photoperiod genes and the stability of wheat growth period and main agronomic traits was analyzed.The following research results were obtained:1.The distribution frequency of dominant allelic variation of vernalization gene in Jiangsu wheatis Vrn-D1a(57.9%)?Vrn-D1b?(15.8%)?Vrn-A1b(5.3%)?Vrn-B1?(2.6%)and Vrn-B3(0%).There are 6 allelic variation combinations of vernalization genes:vrn-A1/vrn-B1/Vrn-D1a(56.1%)?vrn-A1/vrn-B1/vrn-D1(21.1%)?vrn-A1/vrn-B1/Vrn-D1b(15.8%)?Vrn-A1b/vrn-B1/vrn-D1(2.6%)?vrn-A1/Vrn-B1/vrn-D1(2.6%)and Vrn-A1b/vrn-B1/Vrn-D1a(1.8%)?2.The distribution frequency of Vrn-Dla is the highest in Huainan wheat region of Jiangsu,reaching 77.5%.The combination of vrn-A1/vrn-B1/Vrn-D1a(75.0%)dominates.The distribution frequency of Vrn-D1b is the highest in Huaibei wheat region of Jiangsu,reaching 38.2%.The combination of vrn-A1/vrn-B1/Vrn-D1(50%)and the genotype of vrn-A1/vrn-B1/Vrn-D1b(38.2%)were dominant.From 1940 to 2016,the number of winter genotype varieties in Huainan wheat region gradually decreased until they disappeared,while the number of spring genotype varieties gradually increased and the springiness gradually increased.3.In Ppd-D1 locus,Ppd-D1a(93.9%)is the dominant photoperiod insensitive gene in Jiangsu province,while Ppd-D1b,the photoperiod sensitive gene,was eliminated in the early stage of modern breeding.All varieties at Ppd-Al and Ppd-B1 sites carry photoperiod sensitive genes Ppd-Alb and Ppd-B1b4.The seedling phase of varieties carrying dominant vernalization genes Vrn-A1,Vrn-B1 and Vrn-D1a at seedling stage is more inclined to erect and has poor cold resistance,and the jointing stage and heading stage are earlier.The phenotype of varieties with all recessive vernalization gene loci is generally winter,and the seedling phase at seedling stage is prone to creeping with strong cold resistance and longer growth period.The variety carrying only Vrn-D1b is between the two.The vernalization effect of dominant allelic variation of vernalization gene is as follows:Vrn-Al>Vrn-B1>Vrn-D1A>Vrn-D1B.The varieties carrying photoperiod sensitive gene Ppd-D1b were late in jointing and heading stages.Moreover,the correlation between photoperiod gene and heading stage is greater than that of jointing stage5.Under different sowing date treatments,varieties carrying dominant vernalization genes Vrn-A1,Vrn-B1 and Vrn-Dla changed greatly at jointing stage and heading stage and had poor stability at growth stage.The varieties carrying Vrn-D1b gene and vernalization gene are all recessive with relatively small changes at jointing and heading stages and relatively stable growth stages.The 1000-grain weight of varieties carrying photoperiod sensitive gene Ppd-D1b is relatively stable...