Studies On The Genetic Correlation And The Of Selection Effect For Main Traits In Wheat

This paper survey the yield,the yield components and its agronomic characters of new wheat cultivars (lines),which were in for 2006-2007 Regional Test in Jiyuan,Henan. The yield with its agronomic characters of the wheat cultivars (lines)were analyzed by statistics,correlation and path analysis Results indicated.1.the ANOVA in all characters of new wheat cultivars(lines) tested were Significant;Fourteen agronomic characters were of higher Coefficient of variation. these agronomic characters were three upper leaf area,1000-grain weight,the number of kernels per ear,the peduncle length,the length of top first Sheath,the length of top second Sheath,the weight of top second Sheath,the weight of top second leaf,the length of top third knot,the length of top third Sheath,the weight of top third Sheath,the weight of top third leaf. In addition, correlation between yield and eight agronomic characters were significant. The eight agronomic characters were three upper leaf area,1000-grain weight,the number of kernels per ear,the peduncle length,the length of top first Sheath,the length of top second Sheath. Differences of The eight agronomic characters cause the difference of yield. Improving and coordination of the eight agronomic characters is one of the best approaches in breeding for further yield increase.2. The genetic variable coefficient of the plant height,Spike length and so on. They have higher genetic Stability. To improve and enhance these traits,gathering and actively creating new germplasm resources,enhancing the work of identification and selection,and expanding the genetic variability were Indispensable. The method of group selection or mixed-selection is effective to these Low heritability traits,such as yield per plant and the number of ears per hectare. It may be appropriate to relax the selection criteria to get more genetic types in Early-generation. Because they have higher estimates for heritability and lower genetic advance in the length of top first Sheath,the length of top second Sheath,1000-grain weight and so on,they must be strict elect with more plants in early generation3. There were not significant correlation among the number of ears per hectare,grain yield and its agronomic characters. This indicated that the number of ears per hectare close or reach a high threshold. With the path analysis,the direct path coefficient of kernel the number of ears per hectare and the number of kernels per ear were high. This indicated that the number of ears per hectare and the number of kernels per ear were basic factors of yield components. the number of ears per hectare,the number of kernels per ear and 1000-kernels weight should be harmonized to achieve super high and stable yield in breeding of the high yield wheat.4. There were high statistical significance among three upper leaf area. According to this, the flag leaf can be a representative when evaluating and selecting characters of there upper leaf area. Top third leaf area was found to be positive correlation with1000-grain weight. There was a negative correlation between Top third leaf area and grain yield. So improving appropriate three upper leaf area is necessary to avoid excessive diseases by three leaf area causing and achieve sufficient Photosynthetic area. There was a high negative correlation between the grain weight-leaf area ratio. The grain weight-leaf area ratio can be regarded as important criteria of selection in high-yield wheat breeding. It is available to select the type of higher crop yield by using larger ratio of grain weight to leaf area with the appropriate number of ears per hectare in breeding healthy wheat.5. A selection index equation was set up of the 7 traits of impacting yield . Data of genetic advance are estimates in 44 Different combinations of agronomic traits. This combination of agronomic traits was identified as the best combination . the combination of agronomic traits include the first sheath length,spike length and ratio of grain weight to leaf area .Its genetic advance data is high .Every trait in the combination of agronomic traits is all simple and easy to operate. the combination of agronomic traits can be regarded as important criteria of selection in high-yield wheat breeding.