Study Of The Effect Of Opaque-2 Gene On Main Quality Character And Combining Ability Analyses In The Multiple Recessive Homozygotes Sweet Maize

By the method â…£ of Griffing,15 sweet corn hybrids were combined from three multiple recessive homozygotes sweet maize inbreds and three o2 multiple recessive homozygotes sweet maize inbreds. The quality characters and yield characters were measured and the combining ability of these characters were analyzed, to study the effect of o2 gene on the main characters. The results of this study were as follows:1.The performance of main characterThe days to tassel,pollen,and silk of the hybrids combined from two o2 multiple recessive homozygotes sweet maize inbreds were longer than the hybrids combined from single o2 multiple recessive homozygotes sweet maize inbred. The plant height and ear height of hybrids combined from multiple recessive homozygotes sweet maize inbreds with single or two o2 gene were shorter than the hybrids combined from multiple recessive homozygotes sweet maize inbreds without o2 gene. The o2 gene can reduce the plant height. The yeild of hybrids combined from multiple recessive homozygotes sweet maize inbreds with single o2 gene were improved, while hybrids with two o2 gene were reduced. There was no significant difference among the three types of conbinations on the lysine content.The reduced trend was found on nessential amino acid,nonessential amino acid and total amino acid content in hybrids combined from o2 multiple recessive homozygotes sweet maize inbreds. o2 could reduce the contents of nessential amino acid,nonessential amino acid and total amino acid. o2 gene had a trend of improving the soluble total sugar. It was shown that the effect to enhance the content of lysine was insignificant for the maize germplasm with a little endosperm by introducing o2 gene.2.The analyse of combining abilityNessential amino acid, nonessential amino acid, total amino acid and kernel row were controled mainly by additive effect, only Gca variances were significant. The Gca and Sca variances of the days to tassel, days to pollen, days to silk, plant height, ear height, ear length,length of bald tip, number of kernels per row, kernels row, fresh bract weight, fresh ear weight and soluble total sugar were significant. The additive effect and dominance effect controled these characters.The regular of observation was not completely consistent with the Gca or Sca effect. But the regular was general con-sistent with the Tea effect.3.The analyses of the heritabilityThe additive variances of plant height, ear height, nessential amino acid, noness-ential amino acid and total amino acid were higher than the dominance variances. The additive effect impact on the heredity mainly and the narrow-sense and broad-sense heritability over 50%, so thses characters could be choosed at early generation. The additive variances of days to tassel, days to pollen, days to silk, ear length, length of bald tip, fresh bract weight, fresh ear weight,number of kernels per row, kernel row and soluble total sugar were lower than the dominance variances, the additive effect and dominance effect both controled on the heredity, mainly by the dominance effect. The narrow-sense heredity were lower than 50%, the broad-sense heritability(except kernel row) was high, these characters can produce heterosis.4.The analyses of characters correlationsFresh bract weight was significantly correlated with plant height, ear length and the number of kernels per row. The correlation between fresh bract weight and the days to pollen was significantly negtive. There was no significantly correlations betw-wen fresh bract weight and the main quality characters.Soluble total sugar had no significant correlation with nessential amino acid and total amino acid.