Effects Of Different Production Regions On Formation Of Seed Vigor In Conventional Rice

In order to clarify the differences and forming foundation of seed vigor of conventional rice in different regions and provide the index basis and theoretical reference for determining suitable sowing quantity and economical production cost in different ecological regions,field experiment was carried out with four indica cultivars(Zhaongjiazao17,Zhongzao39,Zhongzao35,Xiangwanxian12)and two japonica cultivars(Zhendao11 and Xiushui09)as the material at Changsha(CS),Hechi(HC),Ji'an(JA)and Ruian(RA)in 2015.Seed vigor,1000-grain weight,seed inclusions(protein content,total starch,amylase content and soluble sugar)was determined in the lab of plant physiology and molecular biology,Hunan Agricultural University in 2016.The paper was analysis the correlation among seed vigor,physiological indexes and meteorological factors.The main results were shown as follows:(1)Higher seed vigor traits of conventional early rice were observed in the JA and RA,seed vigor of the JA and RA was significantly higher than that of the CS and HC.Highest seed vigor traits of late Japonica rice among all sites were the JA,highest and lowest seed vigor traits of late Indica rice was the HC and RA,respectively.(2)There were significant differences in the main meteorological factors during the filling period.In the early rice experiment,the daily mean rainfall of the JA(8.7mm)was significantly higher than that of other three sites(5.28~6.09mm),average temperature in the HC was 28.5°C,which was significantly higher than that of other sites.In the late rice experiment,maximum and minimum daily rainfall of the conventional Indica rice cultivars was the RA(5.81mm)and HC(1.77mm).Higher daily rainfall of late Japonica rice was the HC(4.68mm).(3)There was a positive significantly correlation between seed inclusions and seed vigor.In conventional early rice,there was a significantly positive correlation between seed vigor index and total starch(R~2=0.42,p<0.05),and amylase(R~2=0.38,p<0.05),positively correlation between seed vigor index and 1000-grain weight(R~2=0.29)was also observed.In conventional late rice,there were a significantly positive correlation between seed vigor index with total starch(R~2=0.73,p<0.01),and 1000-grain weight(R~2=0.64,p<0.01).However,negatively correlated between seed vigor index and the soluble content was observed(R~2=0.52,p<0.05).(4)The difference of seed vigor among all sites had a connection with the variation of meteorological factors.Meteorological factors would directly affect the seed vigor or indirectly affect the enrichment of seed grain.In the early rice experiment,there was a positive correlation between the seed vigor index and the daily rainfall(R~2=0.48,p<0.05).In the late rice experiment,there was a negative correlation between the seed vigor index and the daily rainfall during grain filling period,but the correlation was not significant.In conclusion,the character of high seed vigor were more protein,total starch,amylase and lower soluble content;regions have different effects on different types of seed vigor;adjusting temperature by the precipitation could affect the formation of seed vigor.