Identification And Evaluation Of The Main Agronomic Traits On Foreign Eggplant Germplasm Resources

Eggplant (Solanum melongena L.) was one of the most important vegetables in many countries of Asia and Africa with rich nutritions and great health functions. China has been recognized as secondary center of eggplant origin, and also has rich eggplant germplasm resources. However, it is still lack of specific germplasm resources, especially those cultivated in protected field with high quality and tolerance to low temperature. On the one hand, introduction of foreign eggplant germplasm resources could solve problem on the lack of relevant resources in China, on another hand, it laid a solid foundation for domestic eggplant germplasm enhancement and long-term reserves to guarantee and promote the sustainable development of eggplant industrialization. Agronomic traits evaluation takes the advantages of simple operation and also is the basic method and way for germplasm resource research. One hundred and forty two kinds of foreign germplasm resources were classified by Q-type cluster analysis and R-type cluster analysis. At the same time, soluble sugar, soluble protein, Vc and Vp were also determinated in this experiment. In addition, the electrical impedance spectroscopy (EIS) was first used to determine cold resistance on 41 kinds of eggplants. The main results were as follows:1 According to data and description from 28 agronomic characters, containing plants, leaves, first flower node et al. Descriptive statistics by spss 16.0 indicated that there were big differences in agronomic traits between the different eggplant germplasm resources. The range of plant height were largest, up to 88m. The coefficient of variation of ribs, fruit calyx needling and leaf needling were the highest. The variation range of fruit color and fruit type were largest in all fruit traits, up to 69.6% and 75.5%, respectively.2 Q-cluster analysis by the genetic distance from 28 agronomic characters of 142 eggplant germplasm resources indicated all the resources were classified into 2 groups: the first group included 701-1 only, and the second group was divided into 5 subgroups. R-cluster analysis by the correlation coefficents divided 28 traits into 5 groups: Group I mainly reflected factors for measuring on traits length, including leaves, fruits, flowers and plants. Group II reflects the subsidiary characters, including fruit calyx needlings and leaves needlings. Group III and groups IV were for leaf color and index of leaves shape, respectively. Group V were for the color factor, such as sepal color, stem color and leaf vein color.3 According to correlation analysis of R-cluster results, the traits such as fruit length, fruit color, fruit type, flower color, plant height, branching, stem color and leaf length were selected as typical traits in the research. 142 germplasms by Q-cluster analysis from the new traits were classified to 2 groups: the first group included 701-1 only, and the second group was divided into 9 subgroups, and the results were similar to Q-cluster’s. Moreover, varieties from different areas were found in the same types, and the distance among the areas were remote.4 The determination results on soluble sugar, soluble protein, Vc, Vp of 142 eggplant germplasm were as follows: the average of soluble protein content was 0.34mg/g, coefficient of variation was 72.0%, but with the minimum range: 1.73 mg/g; the average of soluble sugar was 14.38mg/g, coefficient of variation was 24.5% and the range was 19.27mg/g; the average of Vc was 3.44mg/100g, coefficient of variation was 36.4% and the range was 3.22mg/100g; the average of Vp was 89.2mg/g, coefficient of variation was similar to Vc, 39.2%, but with the maximum range: 161.5mg/g.5 Determination of 41 eggplant leaves by EIS showed re was the most suitable electrical impedance parameters for the determination of cold resistance of eggplant. The result about cold resistance of 41 eggplant germplasms indicated the main sources were-3℃~-6℃, and there were two hardy varieties, and three the non-hardy varieties: the semilethal temperature of 610 and 616 were-10.01℃and-9.88℃, respectively; and that of 648, 690, 699 were -1.8℃,-0.61℃and-1.85℃, respectively.6 The correlation analysis of on quality traits, cold resistance and main morphological characters and data of main agronomic traits indicated that that the eggplants which have tall plants, large leaves, early maturity could resist to lower temperature, and also had a relatively high soluble protein content, but had lower Vp content than long eggplant.At the same time, there exists some specific sources: 681 and 682( with high soluble protein content), 694 and 707( with high soluble sugar content), 630 and 636(with high Vc content), 629 and 701-1(with high Vp content), 610 and 616(with high cold resistance) which could be used for genetic study and breeding practice on quality breeding and resistance breeding.