A Preliminary Study On The Effects Of Seed Starch, Protein, Fat Content On Seed Vigor Of Hybrid Rice

Up to date, there are few reports about the effects of the chemical composition on seed vigorof hybrid rice. This study aimed to investigate the effect of chemical composition on seed vigor ofhybrid rice and elucidate the typical chemical characteristics that high vigorous seeds should have,which will provide scientific basis for breeding new hybrid rice varieties with high vigor.Twohundred and twenty three varieties hybrid rice cultivars were collected from12provinces in China,including Zhejiang, Jiangsu, Anhui, Jiangxi, Hunan, Hubei, Guangdong, Sichuan, Guangxi, Fujian,Guizhou, Liaoning. To evaluate seed vigor, standard germination tests and accelerated aging testwere conducted. Through analysis,12cultivars with high vigor and12cultivars with low vigorwere screened out. The total starch content, amylose content, amylopectin content, protein contentand fat content were determined. Finally,correlation analysis between chemical compositions andvigor indices was performed. The conclusions were drawn as follows.1. Seed vigor evaluation: Combined the results of standard germination and accelerated aging,12varieties including Bayou8, Yongyou9, Yongyou12, Jiayou5, Liangyou932, Wandao181,Fueyou6981, ChuanGuyou202, Huayou18, Teyou837, HNO463and JingChuyou754hadhigher vigor while12varieties including Dianza35, Yongyou10, Dianyou35, Dianza31,Cliangyou1102, QuanLiangyou3, ZhongZheyou8, WuFengyouhuazhan, Tixiang1577, Yiyou5,TeYouhang1and Wanyou2had lower vigor.2. Determination of chemical contents: In24varieties, Bayou8and Jing Chuyou754had thehighest total starch content while Dianyou35had the lowest. Amylose content of HNO463wasthe highest while that of Yongyou10was the lowest. Amylopectin content of Yongyou10was thehighest while that of HNO463was the lowest. Protein content of Dianyou35was the highestwhile that of Chuan Guyou202was the lowest. Fat content of Teyou837was the highest whilethat of Dianyou35was the lowest. The results of T test showed that amylose contents andamylopectin contents of seeds with high vigor were significantly higher and significantly lowerthan those with low vigor, respectively. However, no significant differences were found in thecontents of protein, fat, total starch. The results suggested that amylose content and amylopectincontent had greater effects on seed vigor of hybrid rice.3.Analysis of the relationship between chemical contents and seed vigor indices: Amylose content was significantly or very significantly positively correlated with4vigorindicators.Amylopectin content was significantly or very significantly negatively correlated withvitality indicators (except with aging germination rate). There were negative correlations betweenprotein, fat content and all four vigor indices. But significant correlations only existed betweenprotein, fat content and germination potential, germination index. The above results suggested thathybrid rice seeds with high vigor should contain higher amylose and lower amylopectin content,and then contain lower protein and fat content.