Analysis Of The Genetic Effect On Kernel Dehydration Rate By Using Lancaster To Improve Suwan Germplasm In Maize

The kernel-filling and dehydration rate are two of the mainly indexes during maize breeding progress.According with develement of economiclly breeding,maize hybrids have been largely used in mordern agricultural production.In southwestern region,Suwan germplasm were widely used during enconomic breeding.However,indreds derived from Suwan germplasm always showed some limits,i.e.slower of dehydration rate and vulnerability to maize ear rot,which will be against to the widely used of these lins in agricultural production.Otherwise,Lancaster germplasm showed the advantages of long ear,strong disease-resistance,wide adaptability,fast rate of dehydration and high yield.Therefore,dissecting the changing of kernel-filling and dehydration rate of germplasm derived from Suwan and Lancaster,then released inbreds and relevant hybrids with better kernel-filling and dehydration rate.The research would be important for maize development and harvest by using machines in the southwestern region of China.In this study,the genetic mating design of NCII was used,30 bybrides crossed by,with 16 inbreds from Suwan and Lanscaster groups,respectively to be as female-parent,and QB506,PH6 WC to be as male-parent,were selected as experiment materals.Then,ten major agronomic traits,including kernel-filling,dehydration,were phenotyped under multiple environments,the corelation ship between any pair-traits were analyzed.Major results were showed as follows:1.For kernel filling and dehydration rate,there existed significant variances between different pair-periods after pollination.Much more differneces were found in 39 days after pollination.2.The pattern of kernel dehydration rate varied between hybrids derived from different heterotic groups.For hybrids crossed Suwan with Reid inbreds,the largest dehydration rate appeared in 25-32 days after pollination.The later dehydration rate of hybrids crossed from Lancaster and Reid inbreds,was higher than that crossed from Suwan and Reid inbreds.The dehydration rate showed significantly different between hybrids from Suwan-drived lins crossed with Reid and Suwan germplasm crossed with Reid lines.3.For hybrids from the same femal-parent lines and different male-parent lines,the changing pattern of dehydration rate showed significantly different.For instance,hybrids crossed QR273 with PH6 WC,the largest value of dehydration rate was found in 32-39 days after pollination.While for hybrids crossed QR273 with QB506,the the dehydration rate was found in 25-32 days after pollination.4.There was significant correlation among kernel dehydration rate and 100-kernel weight,cob moisture,bract moisture,ear length and ear width.Of which,correlation coefficients were negative between dehydration rate and kernel-filling rate,100-kernel weight,cob moisture and bract moisture.In addition,the relation-ship beween dehydration rate,kernel-filling rate and 100-kernel weight were complexly,which can not be detected by using since simple linear analysis,but can be detected by using multiple linear stepwise regression analysis.Above all,these results would provide lots of data supporting for dissecting the corelation-ship of dehydration and kernel-filling rate for bybrids derived from different types of germplasm.In addition,these results would also provide some scientific proofs for the the improvement of maieze dehydration and kernel-filling rate.