| The phaseolus vulgaris agglutinin(PHA)content in Phaseolus vulgaris pods is a quantitative trait controlled by multiple genes.The PHA content is affected by factors such as the genotype,growth environment,and harvest time of the bean.It is difficult to reveal the genetic mechanism of PHA content in essence by using traditional genetic research methods.Association analysis based on natural population is an effective method about plant quantitative traits.In this study,with 364 varieties of Phaseolus vulgaris were used as materials,the PHA content in fresh pods were measured using an improved hemagglutination method,and genetic diversity was analyzed.At the same time,the PHA content in pods,pod walls and seeds of different varieties at different developmental stages was measured to Study the change law of PHA content.150 of 364 varieties were used as test materials.Based on the PHA candidate genes related to the PHA content,the association analysis between the nucleotide polymorphisms of the PHA gene in different Phaseolus vulgaris varieties and the PHA content was carried out to discover functional SNP sites.The results showed that:1.The variation of PHA content in Phaseolus vulgaris in the biennium was 0.004 ~ 1.949 mg / g,the coefficient of variation was 0.545,and the average level of PHA content was about 0.653 mg / g.The level of PHA content in the Phaseolus vulgaris cultivars was extremely different,showing significant germplasm specificity and genetic diversity.The overall performance of PHA content in bean germplasm in two years was relatively consistent,and the amount of germplasm resources with extremely high and low PHA content was very small.Phaseolus vulgaris can be divided into three categories according to PHA content based on cluster analysis results,and the PHA content of most bean germplasm(type II)belongs to the medium PHA content(0.500 ~ 0.999 mg/g).2.There were significant differences in the PHA content of the eight bean varieties ’17’,’Hong fu’,’Genoa’,’A18-1-2’,’Silver bar’,’Ten grains’,’Purple crown’ and ’White pearl’ at different developmental stages,but they all appeared with the growth and development of the pods.It showed the same trend,and all peaked at 14 days after flowering.There are significant differences in the PHA content of at different developmental stages.However,with the growth and development of pods,the same trend appeared,and they all peaked at 14 days after flowering.During the growth and development of Phaseolus vulgaris,there are some differences in the PHA content of purple crown and white pearl in pods,pod walls and seeds of ’Purple crown’ and ’white pearl’.And the PHA content of ‘Purple crown’ is lower than that of ‘White Pearl’ in pods,pod walls and seeds.The expression level and PHA content of the ’Purple Crown’ and ’White Pearl’ showed the same trend with the growth and development,and the "double peak" phenomenon appeared.And the expression level of PHA gene of ’White Pearl’ is higher than that of ’Purple Crown’ in multiple stages.3.By analyzing the 60 SNP loci of PHA candidate genes and the PHA content,it was finally obtained that the SNP loci PV14 was extremely significantly correlated with the PHA content.The locus PV14 is G / G genotype,and the PHA content is low to medium.Of the 20 varieties,7 have a PHA content of medium level,and 13 have a low PHA content.The C / C genotype had significantly higher PHA content than the G / G genotype.Therefore,site PV08 can be used as one of the important markers for PHA content types in bean breeding. |
