Analysis Of Heterosis And Combining Ability Of Tomato Inbred Line

Tomato（Solanum lycopersicum L）,the origin is located in South America.As one of the most common vegetables in the world,it is grown both in China and around the world.With the continuous improvement of people’s living standards,breeders are also required to continuously improve the screening and utilization of tomato germplasm resources.In addition to relying on the selection of conventional high-yield new varieties and high-efficiency cultivation techniques and models,the selection and popularization of hybrids are also hot spots in tomato breeding research.The utilization of tomato heterosis can not only improve the breeding efficiency,but also shorten the breeding cycle.In this study,this study mainly screened through heterosis and combining ability analysis,selected 10 excellent parents with corresponding target traits,and obtained 45 hybrid combinations according to the Griffing IV incomplete double-row design,using random The method of repeating the block three times carried out the yield,early maturity,quality heterosis（mid-parent advantage,control advantage,off-center advantage）and combining ability（general combining ability,special combining ability）of all F₁ hybrid combinations and their parents The main research and analysis,with a view to select out the strong advantage combination with high combining ability.The main findings are as follows:In this study,10 excellent parents with corresponding target traits were selected based on the screening of strong combination by combining ability and heterosis analysis.According to the incomplete double-row design of Griffing IV,the F₁ of the 45 hybrid combinations was obtained.The block group conducted 3 studies and analyses on all F₁combinations and their parents including yield,early maturity,quality combining ability（general combining ability and special combining ability）and heterosis（mid-parent advantage,control advantage,off-center advantage）,etc.With a view to screening out strong combination with high combining ability.The main findings are as follows:（1）The combination with strong heterosis was selected,and the heterosis performance of different traits of tomato was different.Among them,the control heterosis of yield traits all showed positive heterosis,and 44.4%and 51,1%showed positive heterosis of mid-parent and over mid heterosis respectively.The control heterosis,mid-parent heterosis and over mid heterosis of early yield were 53.3%,51.1%and 53.3%.The quality control advantage,mid parent heterosis,and over mid heterosis are 86.7%,31.1%,and 60%.（2）Parents with high general combining ability were selected,and the 8 parents with good agronomic traits were:17904,17969,17942.The effect value of general combining ability in the early maturity traits is relatively large,which can be used as a good choice of parents For 17904,17969,17896.Generally,the combining effect value of quality traits is relatively large,and suitable parent materials for improving quality traits are 17648,17904,17969,and 17896.（3）The combinations with high special combining ability were selected.The combination of17666×17648 was excellent in plant height,early yield,total yield,and single fruit weight.The combination of 17719×17955 and 17927×17969 were excellent in maturity,and the combination of 17896×17904 meets the evaluation criteria of excellent hybrids on soluble solids.The above hybrid combinations with excellent traits can be used to improve the target traits of their parents before assembling hybrids and further use as germplasm resources.（4）The 10 parents were divided into three groups by cluster analysis of agronomic traits and general combining ability.Among them,17719,17896,17927,17904,17942,17955 and 17996 are divided into the first group,17666 is the second group alone,and 17969 and 17648 belong to the third group.（5）Select the combination with strong advantage in total yield:17942×17969,17955×17969,the combination with strong advantage in early yield:17666×17648,17955×17969,the combination with strong advantage in mature period are 17896×17904,17896×17648,17942×17969 The combination of 17719×17955and 17927×17969 with strong hardness is 17969×17648,17719×17904,and the combination of soluble sugar is17719×17927,17666×17927,17896×17904.The combination of 17666×17648 was excellent in plant height,early yield,total yield and single fruit weight.