Heterosis And Inheritance Of Main Quality Characters Of Tomato

The research draw on the 1/2P(P+1) Diallel Data design studied the heterosis,combining ability and genetic correlation of 12 quality characters of tomato. The results were summarized as follows:1 Five different parents and their hybrid combinations add up to 15 genotypes to analyze the heterosis and the combining ability of 12 quality characters, and the results showed:1.1 The analysis of heterosis indicated that the heterosis of quality characters of tomato was quite extensive. ASI had strongly positive heterosis as well as fruit hardness, lycopene content, total sugar content and fruit index. Fruit width showed negative heterosis, and other six quality characters had the same level between positive heterosis and negative one. Heterosis degree of different characters was different. The heterosis of ASI was the most evident one of all. The standard deviatio of different crosses was different.1.2 The variances of general and special combining ability were significant or extremely significant except the variance of special combining ability of Vitamin C content. It's indicated that these quality characters were influenced by the add effect or non-add effect of gene or both ones.There was greatly difference among various characters on general combining ability, and so was variance of specific combining ability. We could comprehensively evaluate parents according to general combining ability and specific combining ability variances. Parent-0404 was an ideal parent for its good characters. Parent-0402 was an ideal stuff for processing tomato. 1.3 The general heritabilities of fruit flesh thickness, fruit hardness, lycopene content, fruit width, Vitamin C content, fruit index, fruit length, S/A, titrable acid content, ASI, soluble solid content and total sugar content were 84.12%, 93.57%, 78.93%, 85.28%, 61.49%, 82.59%, 64.85%, 72.79%, 57.00%, 69.54%, 31.72%, 58.81%; Their narrow heritabilities were 70.18%, 66.64%, 65.04%, 64.92%, 61.23%, 39.27%, 26.38%, 23.99%, 22.61%, 2.72%, 1.84%. Both general heritabilities and narrow heritabilities were high in Vitamin C, lycopene content, fruit hardness, fruit flesh thickness, fruit width and fruit index. These quality characters could be chosen in early generations. But the other characters were low in narrow heritabilities, so they should be chosen in high generations.2 We choose 15 genotypes of tomatoes to analyze the genetic correlation of 12 quality characters, and the results showed:The correlations were not significant between soluble solid content and the other characters. Lycopene content had positive correlation with Vitamin C content, fruit hardness and fruit index .The correlation coefficient between lycopene content and fruit width was -0.9367. Fruit flesh thickness was extremely correlative with fruit hardness ASI had positive correlation with fruit hardness, and the coefficient was 0.6530. ASI was extremely correlative with titrable acid content, which had a bigger influence to S/A. Fruit index had significant positive correlation with Vitamin C content, Fruit hardness, lycopene, fruit flesh thickness and ASI, so we need pay attention to the choice of high fruit index in quality breeding of tomato.