Population Improvement Of Sweet Corn And Combining Ability Analysis Of Selected Inbred Lines

Sixteen sweet corn germplasm resources were used to synthesize sweet corn population in this study.Eight inbred lines with high genetic difference which selected from the population after 6 generations of selfing were used by Griffing IV incomplete diallel design.The main agronomic characters and yield characters were measured,Combining ability and genetic parameters were analyzed.The main results are as follows:1.The genetic basis of population basic resources synthesized in this experiment is rich and diverse,inbred breeding has experienced cold resistance,heat resistance,resistance to the adversity.The results show that the improvement of population mixed selection,as the number of cycles increases,bare plant,lodging,susceptible rate and male strain rate decreased significantly in coordination,high quality plant rate showed a significant upward trend,Plant height and ear height decreased.The range of plant type traits of 61 inbred lines was larger,coefficient of variation is also large.The variation range of ear characters was also larger,the variation coefficient of bald tip length and the number of rows were larger.The results showed that the population had some effect on the improvement of the characters,it can improve the efficiency and breeding level of sweet corn inbred lines.2.The combining ability of main agronomic traits and ear traits of the tested inbred lines were analyzed.The results showed that the general combining ability of main agronomic characters of sweet corn was different.M33 and M3 had higher GCA value of plant height,M5 and M2 had higher GCA value in ear height,M3 and M4 had larger GCA value in stem diameter,M4,M2 male tassel length GCA effect value is bigger,M119 and M114 ear leaf angle GCA is smaller;M2 and M114 had a larger GCA value of single spike net value,M2 and M4 had higher GCA value of spike length,M3,M5 bald length GCA effect value is small,M114 and M5 had larger effect on ear diameter GCA value,M2 and M119 had larger effect on the kernels per row.3.The effect of combining ability of the same inbred lines with the same character was complex,there are differences in the size of the effect and the direction of positive and negative effects,analysis and determination of combining ability must be emphasized in breeding practice.There was no direct relationship between the general combining ability and the special combining ability,the measure of a combination of good and bad indicators is the combined effect of the two values.4.A comprehensive evaluation of the utilization value and application potential of the tested inbred lines was made.M114 and M55 were better inbred lines with improved plant height traits,M2 is a kind of inbred line with high ear height and ear length,increasing stem diameter and increasing panicle length;M2 was a good inbred line with a single spike weight and panicle length;M5 is an excellent inbred line with improved bald length and ear diameter traits,M119 is a good inbred line with better the kernels number per row.We should make effective use of it in breeding improvement.5.The results showed that the broad heritability of ear height,ear length,stem diameter,plant height,ear diameter and ear length were larger,the environmental impact is relatively small.The broad heritability of tassel length,net weight per spike,kernel number per row and bald length were low,affected by the environment is relatively large.The narrow heritability of ear diameter and ear length were 62.86% and 56.27%,respectively,more than 50%,can be selected in early generation.The narrow heritability of other traits was less than 50%,not suitable for early generation selection.Heritability plays an important role in the selection of breeding programs and the improvement of selection.