Inheritance Of Plant Type Characteristics And The Relationship Between Plant Type And Low Light Density Tolerance In Truss Tomato

The experiment was carried out with truss tomato varieties as material,which is plant type with distinct difference.The effect of different low light density on related characteristics of truss tomato strains including geometric structure of plant type,physiological characteristics of plant type;especially the photosynthesis and yield formation was studied. The relations between low light tolerance and plant type of truss tomato were discussed,and the related physiological and morphological indexes to low light tolerance were selected. Through designing the genetic analysis experiment of plant type,the inheritance regulations of main geometry and physiological characteristics of plant type in truss tomato were researched aiming at identify main genetic model of plant type character.The results were as follows:1 Main plant type characters in truss tomatoUnder the conditions of protected cultivation,truss tomato has the characteristics such as compact plant type,smaller leaf area and plant width,shorter and thicker leaves,smaller leaf angle,opening angle and drooping angle and but larger reclinate value compared with the control.With the growth and development of plants,leaf angle increased,reclinate value decreased.However,to the later stage of growth,leaf angle was still lower than the control significantly,but reclinate value was higher than ones significantly.Comparison to leaf angle and reclinate value of different position,it could be found that angle of the upper and middle of leaves in truss tomato was lower than control significantly with larger reclinate value;the angle of low leaf was close to control,but the reclinate value was still greater.And compared with the control,the chlorophyll content in truss tomato was higher,light compensation point was lower;comparison with photosynthetic rate of leaf at the same position,all of truss tomato varieties are higher than those of control,which indicated that leaves of truss tomato could make light use efficiency high.2 Changes of main geometry characteristics of plant type under the conditions of low light.The experiment was carried out with two truss tomato strains as material,which are respectively,erect plant type strains and drooping plant type strains.Comparison to change regulations of geometry characteristics of plant type under the conditions of low light,the results were as follows:2.1 The height and plant width increased with low light treatment,the leaf area reduced in two strains of truss tomato;and the decreasing scope of plant height increment and leaf area in erect plant type strains was less than that of drooping plant type strains.2.2.Under the conditions of low light,leaf angle and opening angle in erect plant type strains are greater than that of control;those of drooping plant type strains were greater than that of control at the seedling,flowering and fruit stage,after the fruit expansion stage,those were lower than the control..2.3.Under the conditions of low light,the leaf angle,opening angle and drooping angle increased in erect plant type and drooping plant type strains,and reclinate value decreased. 2.4.Under the conditions of low light,the setting fruit rate,single fruit weight and yield in two strains decreased.Of which,the reducing scope in erect plant type strains was lower than one of in drooping plant type strains.3 Changes of main physiological characteristics of plant type in truss tomato under the conditions of low lightThe experiment was carried out with two truss tomato strains as material,which are respectively,erect plant type strains and drooping plant type strains.Compared to change regulations of physiological characteristics of plant type under the conditions of low light,the results were as follows:3.1.The chlorophyll content in two strains of truss tomato increased at low light treatment,and that of erect plant type strains was higher than drooping plant type strains.The declining extent of chlorophyll content in erect plant type strains was less than that of drooping plant type strains.The results suggested that leaves of truss tomato in erect plant type could maintain physiological functions for a longer time,and delayed the senescence of leaves.3.2.The photosynthesis rate declined in two typical strains of plant type at low light treatment,and decreasing range of erect plant type strains was small.3.3.The light compensation point and light saturation point declined in two typical strains of plant type at low light treatment,and decreasing range of light compensation point in erect plant type strains was larger than that of drooping plant type strains.3.4.Illumination of the erect plant type strains was significantly stronger than that of drooping plant type strains.3.5.The activity of protective enzyme of erect plant type strains leaves of the erect plant type strains was higher,and the content of MDA was lower compared with drooping plant type strains.4 Genetic traits of main plant type characters in truss tomato4.1.Inheritance of the leaf angle was controlled by one additive major gene plus additive-dominance polygene heretary model according with model D-2.Major gene only had additive effects,polygene have both additive and dominance effects.All behaving insynergisim effect,major gene had more effects in F₂ generation,but polygene in B₂ generation had more effects.The heritability ratio of major gene was higher,and the influence of environment was lower.Improving the character of the leaf angle was mainly emphasis on the major gene,so we should select this character in early generation.4.2.The leaf open angle inheritance was controlled by two additive major genes plus additive-dominance polygene models according with model E-3.Major gene only had additive effects,which appeared behaving synergism effect.Whereas additive effects in polygene appeared insynergisim effect,and dominance effects appeared synergism effect. Additive effects were higher than dominance effects.The inheritance of major gene was higher in B₁,B₂ and F₂ colony,which mainly controlled by gene effects,so we should select in early generation.4.3.The leaf droopy angle inheritance was controlled by one additive major gene plus additive-dominance polygene inheritance model according with model D-2.Major gene only had additive effect,which appeared synergism effects.Polygene had both additive and dominance effects,which all appeared synergism effect,and additive effects was higher than dominance effects.The inheritance ratio of major gene was higher in colony F₂ than in other colonies,the inheritance ratio of polygene was higher than major.We should select in early generation for improving the leaf droopy angle.4.4.The leaf reclinate value was controlled by additive-dominance-epitasis polygene model according with model C.The heritability ratio of polygene was higher in colony F₂,the environmental influence was 42.4%,56.61%and 27.81%,there was the greatest influence for colony B₂.We should select in early generation for improving the leaf droopy angle.4.5.The plant width inheritance was controlled by one additive major gene plus additive-dominance polygene inheritance model,which was accordance with model D-2. Major gene only had additive effect,which appeared synergism effect.Additive effects in polygene appeared synergism,and dominance effects appeared insynergsim.Additive effects played a major role in the polygene.The inheritance ratio of major gene was lower whereas polygene was higher.The generation B₁ was the highest in F₂ colony,so we could select in early generation.4.6.The inheritance of leaf area was controlled by one additive major gene plus additive-dominance polygene inheritance model,which was accordance with model D-2. Major gene only had additive effects,which appeared synergism effect,Polygene had both additive and dominance effects,which all appeared synergism effect.Heritability ratio of major gene was 21.6%,3.3%å’Œ16.2%in B₁,B₂ and F₂ colony respectively.The colony B₁ had the highest inheritability,so we could select in early generation.4.7.The inheritance of leaf length was controlled by one additive major gene plus additive-dominance polygene inheritance model,which was accordance with model D-2.The additive effects in major gene appeared synergism effect.Polygenes had additive and dominance effect,which all appeared synergism effect.Heritability ratio of major gene was lower,but the polygene was higher in B₁and B₂ generations.The influence of environment was between 34.68%and 55.88%,so we should select in the early generation.