Study On Identification Of Heat Resistance And Agronomic Traits Of Sweet Corn Inbred Lines

Guangdong Province is the largest production site of sweet corn and has the largest terminal consumer market of sweet corn fresh spike in China.The sweet corn market has great potential for development,so it is of great significance in breeding new varieties in Guangdong Province.Sweet corn originated from the temperate region of North America,most of the sweet corn varieties introduced or independently selected in China are temperate type,which can only be planted in the late autumn or the early spring.During the summer,these varieties will encounter multiple problems including the male flowers abortive,difficulty in spitting of the pistil,or the flowering asynchronism between male and female flowers,so sweet corn cannot be planted in summer.The key to screening heat-resistant varieties is to screen out heat resistant parents(inbred lines).Therefore,373 self bred maize inbred lines from Foshan University were sown on June 24th,2017,to identify the heat tolerance sweet corn inbred lines.On this basis,a total of 62 inbred lines with 13 heat-resistant and 49 not heat-resistant were selected from 373 sweet corn inbred lines and sown on September 1st,2017,and the changing rules of the agronomic traits of heat-resistant and non heat-resistant sweet corn were further analyzed.The results were as follows:1.According to whether the inbred lines produced seeds or not,the sweet corns were divided into two types:heat resistant and non heat-resistant.Of the 373 inbred lines planted in summer,33 inbred lines produced seeds(heat resistant),accounting for 8.85%,and 340(not heat-resistant)inbred lines did not produce seed,accounting for 91.15%.On the other hand,62 inbred lines planted in autumn can normally produce seeds.2.The variation of plant height,ear height,leaves number and number of male flower branches of 62 sweet corn inbred lines were significant difference between summer and autumn,indicating that the above mentioned four agronomic traits were sensitive to high temperature stress.However,the row number per ear was not significant changed between summer and autumn,indicating that this agronomic trait was not-sensitive to high temperature stress.3.There was no significant difference in plant height,ear height,leaves number and branch number of male flower between heat resistant and non heat resistant sweet corn inbred lines.4.There is significant positive correlation between the plant height and the spike height,the plant height and the numbers of leaves,the numbers of leaves and the spike height,the numbers of leaves and the tasseling time,the spike height and the tasseling time,the plant height and the tasseling time.