Comparative Analysis Of Agronomic Traits For Cucumber Chromosomal Segment Substitution Line 42(CSSL42) And Its Recurrent Parent RNS7

Cucumber,known as pickled cucumber as well,is diffusely cultivated as a commercial crop in our country.Cucumber is favored by people by reason of its rich nutritive value,edible value and economic value.Fruit color is a key factor that affects the marketability of cucumber.CSSL42 was obtained in the process of establishing a chromosome segment substitution lines.Compared with RNS7,the fruit color of CSSL42 changed.The agronomic traits were analyzed,and the molecular markers related to fruit color were developed.The regulatory mechanism of cucumber fruit color should be analyzed in the future.In this study,CSSL42 and RNS7 was used as the experimental material to explore its plant growth index(plant hight,stem diameter,first female node),leaf growth index(leaf area,leaf pigment content,photosynthetic and fluorescence parameters),fruit pigment content and fruit quality(sensory quality,nutritional quality and flavor quality),expression levels of genes related to chlorophyll synthesis,as well as the development of fruit color related molecular markers,laying a foundation for fruit color breeding of cucumber.The main findings are as follows:1.There was no significant difference between CSSL42 and RNS7 in agronomic characters(plant height,stem diameter,first female node).2.The leaf area and pigment content of CSSL42 were not significantly different from that of RNS7.The net photosynthetic rate of CSSL42 was significantly higher than that of RNS7.The photochemical efficiency and electron transfer rate of CSSL42 were higher than RNS7,and the thermal dissipation is lower than RNS7.3.At 0 DAA,4 DAA,8 DAA and 12 DAA,the contents of chlorophyll a,chlorophyll b and carotenoids in the fruit skin of CSSL42 were significantly higher than RNS7;At 0 DAA and 4 DAA,the contents of chlorophyll a,chlorophyll b and carotenoid in CSSL42 flesh were higher than RNS7;At 8 DAA,the contents of chlorophyll a and carotenoids in CSSL42 skin were significantly higher than RNS7;The sensory index,nutrition index and flavor index of CSSL42 were better than that of RNS7.4.The expression levels of two genes related to chlorophyll synthesis,Csa3G904140 and Csa3G904130,were higher in the skins of CSSL42 than in RNS7,and the expression levels in the flesh were similar to RNS7.5.Forty pairs of In Del markers were developed at the end of chromosome 3 of cucumber,and twelve pairs of polymorphic molecular markers were selected as fruit color related marker.