| Cotton is the world's leading fiber crop, also it is one of Chinese important economic crops. Breeding high-yield, high-quality, having resistance to disease and pests, and other comprehensive quality traits of varieties cotton plant is the common concern of the breeders. To cultivate new varieties of genetic resources are essential. The 106 progenies come from Cotton G. hirsutum×Darwin and the corresponding parental germplasm lines was used as experimental material. The yield and fiber quality and resistance to Verticillium and wilt were compared and disease resistance traits were analyzed associated with molecular marker, comprehensive evaluated the value of the tested materials, selected a number of excellent germplasm resources, and the results are as follows:1. Yield components:The production of the four upland cotton materials was stable, variation is small. The unginned cotton yield of the different germplasm lines from four groups varies between the wide range, difference between the minimum and maximum were about 2-3 times, lint percent and weight per boll were stable.coefficients of variation were only 0.08 and 13, Boll number give the highest contribution on the yield, but its had larger coefficient of variation, reaching 0.28. Eight yield excellent germplasm lines were screened:HD601, HD622, HD624, HD636, HD648, HD649, HD669, HD690.2. Fiber quality:Fiber quality indicators was more stable, the variation was small, with the variation coefficient only 0.07.It had higher acclimatization. There were transgressive lines, but with a lesser extent. View of all fiber quality traits comprehensive, HD699 had advantages in the UHM (30.9), MIC (4.8), STR (34.5), also the stability between the environment was also very good. HD697, HD707, HD716 were more prominent in the aspects of STR and UHM, with the two indicators values higher than 30, also the ability to adapt to the environment was relatively strong.3. Resistance to Verticillium:In the seedling and adult stage, index of Verticillium of the germplasm lines were lower than the corresponding backcross parent. The gap of the disease index of the adult plant was smaller, but the coefficient of variation was larger, reached 0.45. The parents Darwin's cotton have good resistance, belonging to R resistance level. Take two-year data together, HD662, HD673, HD680, HD701, HD713 were resistant materials, disease index was lower, with the average disease index below 30.The level of disease resistance was excellent.4. Agronomic traits analysis:Seed cotton yield and lint percentage, number of bolls per plant and boll weight was significantly positively correlated, in which associated with the number of bolls per plant had the largest coefficient 0.768. Lint percentage and boll per plant number was significantly correlated. Boll weight and the number of bolls per plant was significantly negatively correlated. Seed cotton yield and fiber elongation was significantly negatively correlated with correlation coefficient -0.203. Lint percentage and the upper-half mean fiber length was significantly negatively related.The number of bolls per plant and the fiber breakage ratio was significantly negatively correlated. Seed cotton yield with the seedling stage disease index and the later disease index were negatively correlated, the higher disease index, the lower yield. Lint percentage was negatively correlated with disease index, but the correlation coefficient was small and less affected. Boll weight was positively correlated with the disease index, and it was significantly related to late disease index. The number of bolls were negatively correlated with the disease, and influenced largely by verticillium wilt. Except micronaire value, the fiber quality and disease index was negatively related, the influence to quality of adult stage than that of seedling stage, the fiber length was affected most.5. Correlation analysis of resistance markers:109 times were linked to the marker loci reaching significant level, belonging to 55 primers, and including 14 BNL series,9 DPL series,8 MUSS series,8 TMB series,4 HAU series,3 JS series,2 CIR series, and the CML, MUCS, NAU series. HAU59b was significantly associated 3 times, and showing positive effect. DPL62a was significantly associated three times, and showing positive effect.16 makers were significant associated, the number of showing for positive and negative effects was six.6. Principal component analysis and clustering:The cumulative variance contribution rate of the first 5 principal components (quality factor, yield factor, disease index factor, etc.)reached 82.27%, of which principal component 1 had the largest contribution reaching 33.43%, it was key factor, followed by the main components 2 and 3, contribution rates were 18.13% and 13.84, the other was main components 5,6,7. The latter six of the principal component had contribution less than 17%, loss of information was limited. The 110 base materials including upland cotton can be divided into four groups. Group members, respectively 22,41,25,22. The main role of clustering was to visually show the agronomic traits of various materials in the field. |
PDF Full Text Request