Study On Heterosis Forecast And Crossing Parents Selection Of Pepper (Capsicum Annuum L.)

Using and predicting of heterosis were the important contents that have been researched by genetics and plant thremmatology , so it was the foundation of pepper breeding . It not only could improve the quality of pepper, gain in yield, but also could save a great deal of manpower, material resources and time that in the field experiment, shorten breeding lifetime, raised the choice effect of hybrid combination. It's upon the foundation of heterosis, correlations and combining ability in agricultural characters and physiological indexes to research forecasting method of yield and qualitative characters of pepper, and then to provide theoretical foundation for crossing parents selection. Eight parents and sixteen hybrids which was carried followed a uncomplete diallel crossing were analysed. The primary results showed that:Firstly, the analysis of agricultural characters on seedling indicated that: Eleven characters had positive super-parents heterosis; R1, R2, R6 and R8 had good performance in general combining ability and they could be considered as excellent parents in agricultural characters. R10, R21 and R23 combinations had good performance on super-parent heterosis and specific combining ability and that could be used in cross breeding; There had significant correlations between individual yield and ten characters and had extremely significant correlations except for stem diameter,the ratio of weekly leaf yield and fresh weight of root. Dry weight of overground part and that of root not only had high over super-parents heterosis but also had high correlation coefficients with individual yield,which arrived at .517**,.505** respectively,both of them should be considered as forecasting indexes of heterosis.Secondly, the analysis of physiological indexes on seedling indicated that: The physiological indexes had positive suer-parent heterosis, excep for soluble protein content and Chl a/b content; Both of R1 and R8 had good performance in general combining ability and that could be considered as excellent parents in physiological indexes; R23, R14, R10 and R21combinations had good performance on super-parent heterosis and specific combining ability and that could be used in cross breeding in the future; There had positive correlations between individual yield and four physiological indexes; SOD activity and soluble sugar content not only had positive suer-parent heterosis but also had extremely significant correlations. So SOD activity and soluble sugar content should be considered as forecasting physiological indexes of heterosis.Thirdly, the analysis of agricultural characters and physiological indexes on adult period indicated that: Early maturity and yielding ability could be improved by heterosis, but it was hard to increase quality characters of friut length, friut width, flesh thickness, dry matter, soluble sugar content, soluble protein content of pepper by heterosis; The analysis of general combining ability showed that each of R1,R6, R2, R8 was ideal parent in individual yield,and both of R2 and R8 should be considered as excellent parents in prematurity combination,and R2,R5, R1 and R6 were good parents performance in quality of fruit, and R6, R7 and R1 were parents with strong growth vigor; It could be concluded by analysis of comprehensive specific combining ability that R21, R14 and R13 were good combinations in the high yield, R23 and R24 in prematurity, R14, R10 and R21 in quality, R24, R21, R23 and R20 in growth vigor; It also could be concluded that Each of leaf length , leaf width, plant height, stem diameter, flesh thickness, soluble protein content had extremely significant correlations with individual yield. So they could be considered as forecasting indexes of heterosis on adult period.