Genetic Study Of Main Characters In Micro-endosperm Super-sweet Super-high Oil Corn

By the design of NC II(North carlina design II),twelve corn hybrids were combined from four inbred lines of micro-endosperm high yield corn and three inbred les of micro-endosperm high oil corn.The agronomic characters,quality characters and yield characters were measuerd and the combining ability,heritability and correlations of these characters were analyzed.Main results were as follows:(1)The performance of main character.All combination have better performance in main agronomic characters excepted combination 6.Some hybrid combinations have positive transgressive advantage in kernel weight and kernel percent oil,majority of their performance were between parents,and towards high value parent.Starch content were declined obviously in maturing period.According to yield character and soluble sugar content in milking period,combination 9 was the best,combination 7 was the second as sweet corn for eating.According to yield character and percent oil characters;combination 9 was better in comprehensive;combination 7 has lower percent oil,but it's grain yield and embryo oil ratio were better,these may leaded out of oil become higher;combination 5 has the highest percent oil,but grain yield was lower.On the whole,combination 9 can regard as super sweet super high oil corn.(2)The analyses of combining ability in main character.In high-yield parent,eighteen characters were at extremely significant levels in Gca(General combining ability)variances excepted kernel moisture content and embryo oil ratio characters.In high oil parent,twelve characters were at significant or extremely significant levels in Gca variances except eight characters—days to silk,fresh ear weight,ear length,ear rows,kernel weight per ear,100-kernel weight,starch content in maturing and embryo oil ratio.For five characters-fresh ear weight,ear rows,kernel weight per ear,starch content in maturing and embryo weight ratio,their Sca(Specific combining ability)were not at significant levels,the rest of the characters were at significant or extremely significant levels.High yield parent 148 has better Gca relative effect in yield relative characters,three combinations made form her have better performance in yield relative characters.High yield parent 136 has better Gca relative effect in oil relative characters,three combinations made form her have better performance in oil relative characters.High oil parent 262 has better Gca relative effect in kernel percent oil,embryo percent oil and non-embryo percent oil,majority combinations made form him have high percent oil.When both parents of Gca and Sca of relative effect value were higher,Their corresponding combinations measured value were higher,and vice versa.Only a few combinations does not conform to the law,however,their Tca(Total combining ability)relative effect and measured value's trend were identical completely.(3)The analyses of the heritability in main character.The broad heritability(h2B)were more than 55%in the researched of main characters,and majority characters Gca of variance were greater than the Sca of variance.Narrow heritability(h2N)'s trend was not the same as broad heritability(h2B)in these characters,namely,when the broad heritability(h2B)was high,narrow heritability(h2N)was not.Ear diameter,kernel percent oil and embryo weight ratio were high both in broad heritability(h2B)and narrow heritability(h2N).(4)The analyses of the correlations in main character.Between plant type and yield character,plant height was extremely significant positive correlation with all yield characters except ear diameter.Between yield characters and quality characters,kernel weight per ear was extremely significant positive correlation with starch content in maturing and oil content per ear,and it was significant negative correlation with kernel percent oil.Between quality characters,kernel percent oil,embryo percent oil and non-embryo percent oil were extremely significant positive correlation between and among them.(5)The analysis of the path coefficient in main character.The direct contribution of various characters to oil content per ear in maturing were kernel weight per ear>embryo percent oil>non-embryo percent oil>embryo weight ratio>starch content.Different from simple correlation,embryo percent oil and non-embryo percent oil have positive direct effect,while starch content in maturing has negative direct effect.These characters direct effect on oil content per ear were showed when the indirect effects ruled out.