Genetic Analysis Of Quantitative Traits In RIL Population Derived From Common Wheat And Semi-wild Tibetan Wheat

Heritability of quantitative traits including the plant height, spike length, spike number per plant, fertilized spikelets per spike, 1000-kernel weight, amylopectin content, total starch content, and ADPGPPase activity had been studied based on the recombinant inbred lines (RILs) derived from Yan Zhan1/Chayazheda 29.The results are showed as follows:1. Heritability for the eight quantitative traits above are 80.10%, 80.00%, 72.52%, 48.28%, 70.10%, 70.14%, 75.42%, 88.12%, respectively. It shows that the heritabilities of plant height, spike length, spike number per plant, 1000-kernel weight, amylopectin content, total starch content and ADPGPPase are high.2. Gene logarithm for the above seven traits are 1-2pairs, 2-3 pairs, 5-6 pairs, 5-6 pairs, 4-5 pairs, 4-5pairs and 2-3 pairs, respectively, which is mainly controlled by additive genetic effects and scarcely influenced by environments. However, the heritability of fertilized spikelets per spike is only 48.28%, which means fertilized spikelets per spike is influenced by environments. The gene logarithm for the fertilized spikelets per spike are 2-3 pairs.3. In addition, the coefficients of skewness (g1) and kurtosis (g2) of those traits were both estimated in this study. The investigations of the genetic models of these quantitative traits showed that there are no gene interactions among the following traits such as plant height, fertilized spikelets per spike and amylopectin content. However, complementary gene interactions probably exist in the traits of spike length and total starch content, and complementary gene interactions are also found in spike number per spike.4. The mean of plant height,spike number per plant,total starch content and ADPGPPase activity are between their parent plants. Coefficients of variation of ADPGPPase activity, spike number per plant and spike length in groups are larger, which are 28.39%,27.42% and 24.43%, respectively. While the coefficients of variation of amylopectin content, total starchcontent are smaller, i. e. 6.01% and 4.75%, respectively.5. Amylose content is significantly related to total starch content in RILspopulation, the correlation coefficient is 0.72. Amylopectin content isrelated to total starch content in the RILs, and the correlation coefficient is0.22. Amylopectin contents and amylose content appear to be negtive,and the correlation coefficient is -0.49. Interestingly, the ADPGPPase in flagleaves is weakly related to either amylopectin content or total starchcontent. The correlation coefficients are 0.16 and 0.09, respectively. Whilethe ADPGPPase and amylose content has negative relationship. Thenegative correlation coefficient is -0.04.6. Two exceptionally meritorious lines were selected from each of thefollowing five characters including 1000-kernel weight, spike length, spikenumber per plant, fertilized spikelets per spike and total spikelets per spike.For example, the 1000-kernel weight in the elite line No.3034 is 61.59g, andthe percentage over the super parent in 1000-kernel weight is 69.89%. Thespike number per plant of No.2967 is 30 and the percentage over ther superparent is 42.86%.7. Both heading and anthesis date of semi-wild Tibetan Wheat Chayazheda29 are later than Yan Zhan1.8. In the comparison between the selected lines and parents, thepercentage over the super parent is highest in the total spikelets per spike,accounting for 5.1%. While, the heading stage and anthesis take the smallestpercentage over super parent, both being 1.02%. The performances of bothspike number per plant and anthesis in RILs are mostly between two parents,both accounting for 91.84%.