Distribution And Characterization Of Agronomical And Quality Genes In Some Wheat Cultivars Of China And CIMMYT

In the present study,Zhou 8425B and its 57 derivatives were analyzed by molecular markers for dwarfing genes and vernalization(Vrn) genes.A total of 273 CIMMYT cultivars and advanced lines were investigated with the gene specific markers for dwarfing,polyphenol oxidase(PPO), phytoene synthase(Psy) and waxy genes.Of them,142 lines were tested with sodium-dodecyl-sulfate polyacrylamide gel electrophoresis(SDS-PAGE),reversed-phase high-performance liquid chromatography(RP-HPLC),and molecular markers for the characterization of high- and low molecular-weight glutenin subunits(HMW-GS and LMW-GS). The results are presented as follows:1.In the 58 Zhou 8425B and its derivatives,Rht-D1b and Rht8 genes were dominant,with frequencies of 86.2%and 58.6%,respecitively,followed by Rht-B1b with a frequency of 13.8%. Four lines contained both of the genes Rht-B1b and Rht-D1b,28 lines had genes Rht-D1b and Rht8,only 1 line possessed Rht-B1b and Rht8,and 3 lines contained the three dwarfing genes.The frequency of dominant gene Vrn-D1 in the 58 lines was the highest(62.1%),followed by dominant genes Vrn-B1(5.2%) and Vrn-B4(5.2%),and dominant gene Vrn-A1 was not detected in these materials.Hongzhan9908 and Hongzhan6816 contain Vrn-D1 and Vrn-B4,respectively,36 cultivars carried one dominant vernalization,20 lines were recessive alleles at the four vernalization loci,no cultivar possession of three or four dominant vernalization.In the 58 lines tested with marker csLV34,No lines possessed the gene Lr34/Yr18.2.In the 273 CIMMYT cultivars and lines,216 lines(82.1%) were detected to have the allele Rht-B1b,and 38 lines(14.4%) contained the allele Rht-D1b.Twenty-one lines possessed both the wild-type alleles Rht-B1a and Rht-D1a,while 12 had two dwarfing genes Rht-B1b and Rht-D1b.In the 273 CIMMYT lines tested with the marker PPO18,216 lines(79.1%) possessed the allele Ppo-A1a and 55(20.2%) contained Ppo-A1b,amplifying a 685-bp and an 876-bp PCR fragment,respectively,and no PCR amplification occurred in 2 lines that may have new allelic variation at this locus.At the locus Ppo-D1 tested by markers PPO16 and PPO29,227 lines (83.2%) contained the allele Ppo-D1a and 46(16.8%) had Ppo-D1b,yielding a 713-bp and a 490-bp PCR fragments,respectively.At the locus Psy-A1,142 lines(52.0%) had the allele Psy-A1a and 131(48.0%) contained Psy-A1b,amplifying a 194-bp fragment and a 231-bp fragment,respectively.Using the marker YP7B for the gene Psy-B1,155(56.8%) and 43 lines(15.8%) generated a 151-bp and a 156-bp fragment for the alleles Psy-B1a and Psy-B1b,respectively,whereas 75(27.4%) lines possessed the allele Psy-B1d detected by marker YP7B-3,generating an 884-bp PCR fragment.For waxy genes,all of 273 lines contained the alleles Wx-A1a and Wx-D1a in the test with the markers MAG264 and MAG269,respectively.At the Wx-B1 locus tested by marker Wx-B1, 204 lines(74.7%) were assumed to have Wx-B1a allele and 69 lines(25.3%) possessed Wx-B1b with the presence and absence of 425-bp PCR fragment,respectively.In the 273 CIMMYT lines tested with marker csLV34,61 lines(22.3%) possessed the gene Lr34/Yr18 and 212(77.7%) had no Lr34/Yr18,amplifying a 150-bp and a 229-bp PCR fragment, respectively.3.Of 142 CIMMYT cultivars and advanced lines tested by molecular markers and SDS-PAGE,a 1319-bp fragment was amplified in 90 lines by molecular marker at Ax2~* locus,indicating the presence of this subunit.Forty-six lines contained subunit Bx17 with a 675-bp fragment amplified by marker BxFp.The primer set ZSBy8F5/R5 specific to the By8 gene produced a 527-bp fragment in 16 lines,and a 662-bp fragment was detected in 57 lines with the subunit By9 tested by marker ZSBy9aF1/R3,while 5 lines contained subunit Bx20 detected by marker MAR with an 800-bp PCR fragment.One hundred and eighteen lines contained subunits 5+10 with a 450-bp PCR fragment. The allele Glu-B3j,associated with 1B.1R translocation,was detected in 33 lines by marker AF1/AF4,generating a 1500-bp PCR fragment.The results in the test with molecular markers were consistent with those of SDS-PAGE,except that one line with 1A.1R determined by SDS-PAGE couldn't be distinguished from 1B.1R in the test with the marker AF1/AF4.In addition,4 lines with By8~* identified by RP-HPLC and molecular marker couldn't be distinguished from By8 with SDS-PAGE.Therefore,20 lines were assumed to have the subunits By8 or By8~* in the test of SDS-PAGE,whereas 16 were detected to contain the subunit By8 with molecular marker.The marker ZSBy8F5/R5 allows discrimination of alleles in a line containing By8 and By8~*.However, the subunits By8 and By8~* have similar electrophoretic mobilities in SDS-PAGE that couldn't tell the subunit By8 from By8~*,which was confirmed in this study.