The Effects Of Vrn-D1 On Wheat Development

Common wheat(Triticum aestivum L.)is one of the most widely cultivated food crops in the world and is grown over a wide range of elevations,climatic conditions,and soil fertility.The wide adaptability of wheat is mainly governed by two gene groups of vernalization(Vrn)genes(vernalization requirement),photoperiod(Ppd)genes(photoperiod sensitivity).To make clear the effect of each Vrn allele and their combination in wheat germplasms is useful for breeding cultivars to accommodate different agricultural regions.This study was to assess the effect of Vrn-D1 locus in wheat.It will be valuable for wheat molecular breeding to improve cultivar adaptability,especially in the most important wheat prduction province Henan in China,a largest wheat producer and consumer country in the world.The plant materials used in this study included a tender spring cultivar ‘Pumai 9’,a semi-winter growth habit powdery mildew resistance line ‘G883’ obtained from Henan Academy of Agricultural Sciences in China,and their offspring of 19 sister lines(SLs).Through analyzing the genotpyes of ‘G883’,‘Pumai 9’ and the SLs at loci Vrn-A1,Vrn-B1,Vrn-D1 and Vrn-B3,Ppd-D1 and growing season surveying(tillering,spike differentiation process(SD),heading date(HD),main stem leaf number,Stable leaf numbers on the main stem(FLN),flowering and maturity),this study was to assess the relationship of Vrn-D1 locus and the development in wheat.The results are as follows:1.In 19 sister lines(SL0-SL18)and their parents ‘Pumai 9’,‘G883’,The loci of Vrn-A1,Vrn-B1,Vrn-B3 and Ppd-D1 were the same in all 19 sister lines except Vrn-D1 locus.2.Dominant Vrn-D1 can weaken the tillering ability of wheat and confine the development of main stem leaf;the recessive vrn-D1 can increase the tillering ability of wheat and accelerate the development of main stem leaf.The alleles at the Vrn-D1 locus significantly affect the final leaf number.Vrn-D1 carrier cultivar ‘Pumai 9’ and SL3,SL4,SL5,SL8,SL9,SL11,SL15,SL16,SL18 had fewer FLN than those vrn-D1 carrier lines of ‘G883’ and SL0,SL1,SL2,SL6,SL7,SL10,SL12,SL13,SL14,SL17 by about 1 leaf in the three treatments.The former’ maximum tillering number is fewer than the latter’s,the value is about one.3.Dominant Vrn-D1 can accelerate the spike differentiation process and the recessive vrn-D1 can restrain the spike differentiation process.4.Dominant Vrn-D1 make the heading date in advance and blossom earlier,mature earlier.The recessive vrn-D1 delay the heading date and make wheat blossom later,mature later.Vrn-D1 carrier cultivar ‘Pumai 9’ and SL3,SL4,SL5,SL8,SL9,SL11,SL15,SL16,SL18 headed earlier than vrn-D1 carrier ‘G883’ and SL0,SL1,SL2,SL6,SL7,SL10,SL12,SL13,SL14,SL17 by about 3 days in the first and second sowing treatments(on 6th October 2011,11 th October 2011)and average 7 days in the Fourth treatment(23th February 2012).In sum,Dominant Vrn-D1 endows wheat tender spring habit and the recessive vrn-D1 endows wheat semi-winter growth habit.These indicated Vrn-D1 is an important locus for molecular breeding,at least in the most important wheat zone Huang-Huai Wheat Zone in China.It is one of the important aspects for wheat molecular breeding to track the Vrn-D1 locus and breeding cultivars to accommodate different agricultural regions.