| The cultivated tomato(Solanum lycopersium L)mostly is a self-pollinated plant with obvious heterosis.At present,the production of the F1 generation is mostly need to artificially remove stamens,so there are problems such as low efficiency and high cost.The long style trait cannot be used for hybrid seeding because of the high stigma of the stamen and is often affected by environmental factors,especially temperature,and cannot be applied to production.Obtaining a stable hereditary long style trait and mastering its inheritance is the precondition for application.In this study,the temperature sensitivity,inheritance and related QTL of the long style trait were analyzed by the tomato(J59)with long style trait preserved by the research group,in order to lay the function for clone,function analysis and production application of long style trait.The main results are as follows:1.Analysis of pollination and fertilization activity and temperature sensitivity of the long style tomato J59.The methods of pollen germination and benzidine-hydrogen peroxide were used to determine the pollen and stigma activity.The germination rate of J59 reached 80.76% and the control germination rate was 60.59%.The results showed that the stigma activity of J59 was not significantly different from that of control.Temperature sensitivity test,the tomato was treated using 18/ 10 °C,25/ 18 °C and 35/ 25 °C temperature gradient at 2 cotyledons and 1 true leaf stage.The results showed that temperature had no effect on the long style trait.In the observation of the elongation process of style of the flower,it was found that J59 showed stigma exsertion over flower bud at 1 day before flowering,and the length of the stigma exsertion from stamen was to 1.45 mm.2.Analysis of the inheritance of long style trait.The 6-generation groups P1,P2,F1,BC1P1,BC2P2 and F2 were constructed with the long-style J59 and short-style M82 as parents.The length of the stigma exsertion from stamen(D-value)indicates the long style trait.The results showed that orthogonal and inverse cross hybrid generation F1 were longstyles,the D-value is 0.79 mm and 0.86 mm,respectively,between the two parents,the mid-parental rate is 54.9%,indicating that the long style is controlled by the nuclear genes,and the long style is dominant to the short style.The genetic analysis of the long style trait(D-value)of the 6-generation population was carried out by using the main gene + polygenes mixed genetic model of plant quantitative traits.The results showed that the inheritance of the long style trait(D-value)was affected by two pairs of additive-dominant-epitogenic major genes + additive-dominant polygenes(MX2-ADI-AD),the major gene heritabilities of the BC1P1,BC2P2 and F2 populations were 65.51%,90.76% and 89.1%,respectively,and the polygene heritability were 0,0 and 0.53%,respectively,indicating that the inheritance of the long style trait(D-value)of tomato is controlled by two pairs of major genes + polygenes.3.QTL mapping of long style trait in tomato.The long style trait(D-value)is a quantitative trait.A genetic linkage map was constructed using 121 pairs of parental differential primers and 465 F2 population.The map covers 12 linkage groups with a total length of 2108.71 c M and an average distance between markers of 17.43 c M.QTL mapping was performed on the long style trait by using the mixed linear composite interval mapping method.When the LOD was 2.5,10 QTLs related long style trait q D-value1-1,q D-value2-1,q D-Value2-2,q D-value2-3,q D-value2-4,q D-value3-1,q D-value3-2,q D-value4-1,q D-value5-1 and q D-value12-1 were detected,LOD between 1.28 and 25.34,the phenotypic variance explained is 1.28-20.22%.Among them,the loci with greater than 10% variance explained are q D-value1-1,q D-value2-2,q D-value2-3,and the variance explained are 20.22%,15.22% and 18.16%,respectively. |
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