Study On The Relationship Between The Changes Of Endogenous Hormones In Wheat Seed Germination And The Seed Vigor

Seed is the most important materials in agricultural production,and high seed vigorwill be contributed to the high grain yield.In our research,71 wheat varieties collected from Yellow and Huai River valleys winter wheat region,Northern winter wheat region,middle and lower reaches of the Yangtze River and Southwestern winter wheat region were used to study the differences of seed vigor in different wheat regions.The content changes of endogenous Gibberellin,Abscisic acid,Auxin and Cytokinin were detected in different germination seeds and the differences of endogenous hormones in different wheat regions were analyzed.Finally,the relationship between the endogenous hormone content and seed vigor was detected by correlation analysis.The results were shown in following:(1)In four wheat regions,the germination rate,germination potential,germination index,vigor index,main root length,fresh weight and seedling length were all higher and germination index,vigor index and seedling fresh weight in the middle and lower reaches of the Yangtze River were 47.72,3.46 and 7.25 g separately,and the seedling length and seedling fresh weight in the Yellow and Huai River valleys winter wheat region were 2.93,10.66 and 6.21 g separately,and very significant difference was detected in in the middle and lower reaches of the Yangtze River and the Yellow and Huai River valleys winter wheat region.The germination rate,germination potential,germination index and seedling length of landrace were higher than those of cultivated varieties,but the difference was not significant.(2)At 6-72 hours after germinationin the four wheat regions,the abscisic acid content of seeds were decreased,but there was no significant difference among the wheat regions at the same period.From 6-48 h,seed content abscisic acid of the southwest winter wheat region decreased the fastest with 0.105?g/g to0.05?g/gin middle and lower reaches of Yangtze River wheat region,the contents of gibberellin in the seeds of 6h,12 h,24h,48 h and 72 h were 234.57?g/g,236.62?g/g,422.25?g/g,1176.19?g/g,1468.41?g/g,respectively,which higher than the other three wheat regions,and auxin content of seeds were0.09?g/g,0.08?g/g,0.14?g/g,0.57?g/g,1.98?g/g,which were higher than other three wheat regions.the zeatincontent of seed in southwest winter wheat region and middle and lower reaches of Yangtze River wheat region were increased,while that in Huanghuai winter wheat region was decreased.(3)From 6 to 72 hours after germination,the seeds contents of endogenous gibberellin and auxin in both landrace and cultivated varieties were increased,while the contents of abscisic acid was decreased.The content of gibberellin in the cultivated varieties was higher than that in the landrace in 6h,12 h,24,48 h and 72 h with 229.25?g/g,221.40?g/g,392.80?g/g,1019.64?g/g,1355.18?g/g in cultivated varieties and162.54?g/g,175.73?g/g,331.99?g/g,846.37?g/g,1236.45?g/g in landrace,respectively.After 24 h,the seed auxin content increased rapidly with 0.07?g/g,0.07?g/g,0.11?g/g,0.58?g/g,1.69?g/g in cultivated varieties and 0.11?g/g,0.12?g/g,0.08?g/g,0.4?g/g,0.91?g/g in landrace,respectively.The seed zein content in landrace was increased but decreased in cultivated varieties.Difference comparison of hormone content showed that the content of auxin,between landrace and cultivated varieties was significant or extremely significant during 6-72 h,the content of gibberellin was significant during 6-12 h,48-72 h,zein content was significant during 6h,24-48 h,abscisic acid content was significant during 12-24 h.(4)After germination24 h,the gibberellin and germination potential,germination index,vigor index and freshwere all significantly positive correlated with the correlation coefficients 0.371,0.353,0.251 and0.385,respectively.The abscisic acidand germination rate,germination index and vigor index at 12 h after germination were all negatively correlated withthe correlation coefficients-0.241,-0.198 and-0.314,separately.The correlation coefficients between the content of auxin and the germination rate were 0.307 at24 h after germination,which was significantly positive.The correlation coefficient between zein and germination rate was 0.272 at 24 h after germination,and the correlation coefficient between zein content and principal root length was 0.386 at 72 h,both of which were significantly positive.(5)The germination rate,germination potential,germination index and vigor index of hybrid wheat were significantly lower than those of common wheat.The content of zein and auxin in common wheat was higher than that in hybrid wheat within 6h-72 h after seed germination,but the content and rising rate of zein in hybrid wheat seed were higher than that in common wheat after 48 h.The correlation coefficients of gibberellin content at 24 hours and 48 hours were 0.620 and 0.696,0.604 and 0.696,0.479 and 0.569,respectively.Germination of 6-72 hours of corn content and germination rate of the correlation coefficient were 0.656,0.617,0.652,0.540,0.605,and the germination of correlation coefficient were 0.752,0.813,0.816,0.629,0.680,and germination index of correlation coefficients were 0.771,0.813,0.828,0.651,0.709,and vigor index of correlation coefficient were 0.662,0.668,0.653,0.539,0.542,were significantlyor extremely significantly correlated;The correlation ratios between auxin and germination rate,germination potential,germination index and vigor index were 0.687 and 0.733,0.746 and 0.803,0.755 and0.846,0622 and 0.734 at 48-72 hours of germination.