Comparison Studies Of Relationships Between Agronomic Traits And Yield, Nutrient Quality Traits On Pumpkins

Pumpkin is one of the major vegetable crops in Cucurbit family. The studies of relationship between agronomic traits and breeding objectives are rarely reported. In this study, the relationship among different agronomic traits of 21 pumpkin cultivars and their contribution to breeding objectives were analyzed with the methods of gray relation analysis, correlation analysis, as well as regression analysis, to identify the effect of different traits on the breeding objectives and provide valuable information for expediting the breeding procession of pumpkin. Besides, many cultivars with the characters of high yield potential, stable yield, high quality and long shelf life were screened by the methods of gray theory including gray relation evaluation, advantage analysis, gray prediction and so on, which set good fundament for cross combination. The main results were as following:1. The highest association degree of the agronomic trait and total yield was the yield per plant. Then, the following order was fruit diameter, flesh thickness of fruit, inner diameter of fruit, fruit amount per plant, water content of matured fruit, stem diameter, skin thickness of seed, sugar content, the days for first female flower appearance, soluble solid content, yield of early period in 2004. The association degree order of traits and yield in early period from high to low was the nodes of first female flower appearance, the days for first female appearance, fruit amount per plant, seed length, protein content, water content of young fruit, stem diameter, seed width, fruit stem diameter, yield pre plant respectively. The association degree of the traits and yield per plant from high to low was flesh thickness of fruit, fruit outer diameter, fruit inner diameter, fruit weight, water content of young fruit, water content of matured fruit, seed thickness, sugar content, stem diameter, fruit amount per plant, days for first female appearance, yield in the early period respectively. The association degree of traits and fruit weight from high to low was fruit outer diameter, fruit inner diameter, flesh thickness, yield per plant, seed length, sugar content, length between nodes, fruit stem length, days of first female appearance, soluble solid content, water content of matured fruit, water content of young fruit, weight per thousand seeds, Vc content of young fruit, fruit amount per plant respectively.2. The cultivars with the high yield potential were 63, D-7, D-3, 70-2, 15-1 respectively. The cultivars with the high yield potential in early period were H-53-1, Y-l-A, 29-A, 70-2, 63. The cultivars with the high yield potential per plant were 70-2, Y-l-A, D-7, 63, 15-1. In contrast to the reference, the cultivars with traits of high and stable yield were D-7, 18, 63, 13-C, H-19-1 respectively.3. Six nutrient quality characters had significant correlationship with 15 field...