Effect Of Bisexual Flower Inducing Of Different Male-inducting Reagent On The Predominately Gynoecious Of Edible Seed Watermelon

Predominately gynoecious plants in cucubits can be used to simplify hybrid seed production.Silver nitrate,silver thiosulfate,gibberellin and mixed reagents(Hi mixed:silver nitrate and gibberellin mixed,H2 mixed:silver thiosulfate and gibberellin mixed)were used as male-inducing agents to induce bisexual flower at seedlings stage of the edible seed watermelon,which provided a theoretical basis for production of parent seed The predominately gynoecious breeding line ’DK1’ of edible seed watermelon were used as the material in the test,the first 1-3 true leaf flattening period of seedlings were treated by silver nitrate at a concentration of 100 mg/L,300 mg/L,500 mg/L and 700 mg/L,300 mg/L,600 mg/L,900 mg/L and 1200 mg/L silver thiosulfate,300 mg/L,800 mg/L,1300 mg/L and 1800 mg/L gibberellin,H1 mixed reagent(nitric acid Silver 100 mg/L+gibberellin 300 mg/L),H2 mixed reagent(silver thiosulfate 300 mg/L+gibberellin 300 mg/L)solution in spraying once,twice and three times respectively,the bisexual flowers and male flowers in the 5th to 20th nodes of the main vines,and the number of female flowers and abortive flowers and the stem leaf growth(length × width,petiole length,internode length,stem diameter,main stem length and chlorophyll content)and fruit growth(the proportion of fruit weight,deformity fruit,fruit grain number)index.Were compared in the different concentrations of different inducing agents and the number of different spraying times,In order to analyze the basic laws of the sexual inheritance of predominately gynoecious in edible seed watermelon,experiment selected strong female system(PA,PC),and normal type(PB,PD)seed melon hybrid parent material,by hybrid Fi,selfing and backcross preparation the 2 groups segregation for sex forms of genetic groups respectively,and the number of normal plants and the predominately gynoecious plants in the segregation for sex forms of plant populations were counted,and the separation ratio was calculated by χ2 test.The results show:(1)The effect of silver nitrate concentration on spraying 300 mg/L for 3 times was the best,with an average of 6.10 flowers per plant.The effect of silver thiosulfate concentration on spraying 900 mg/L for 3 times was the best,with an average of 10.31 flowers per plant.The effect of gibberellin concentration on spraying 1300 mg/L for 3 times was the best,with an average of 4.11 flowers per plant.The concentration of mixed reagents was the best for inducing bisexual flowers by spraying with H1 mixed reagent for 3 times,with an average of 2.59 flowers per plant.Among them,the best inducing effect is silver thiosulfate concentration of 900 mg/L and spraying 3 times,which mixed was poor effect.Effects of silver nitrate and silver thiosulfate on the distribution of bisexual flowers in 5th-10th,11th-15th and 16th-20th sections of predominately gynoecious edible seed watermelon by different spraying times with silver nitrate and silver thiosulfate.After a single treatment,no good inducing was achieved.After silver nitrate and silver thiosulfate were treated twice,after treatment with 900 mg/L thiosulfate,the number of bisexual flowers induced by each node was the highest,which achieved a good inducing effect.After silver nitrate and silver thiosulfate were treated three times,treatment with 900 mg/L thiosulfate,the number of bisexual flowers induced by each node was the highest,and the inducing effect was the best.Among them,the stimulating effect of the silver thiosulfate solution is obviously better than that of the silver nitrate solution,and the production of the predominately gynoecious of edible seed watennelon can be extended by referring to the inducing method.(2)Through the comparison of growth indexes and chlorophyll content of stem and leaf of predominately gynoecious of edible seed watermelon treated with different male-inducting reagent,the results showed that with the increase of concentration of silver nitrate and silver thiosulfate and the increase of spraying times,to predominately gynoecious of edible seed watermelon line 1-3 plants piece of true foliage length×width,petiole;leaf length×width 10,6th-7th internode length,section 6th-7th thick stems and plant main stem length and 2-3 true leaf chlorophyll content showed a trend of decrease,gibberellin and mixed reagent processing with the increase of the number of spraying,1-3 of true leaf petiole length show a trend of increase,influences on the targets of each other to grow in line with nitric acid silver and silver sulfate sulfur generation performance.The effects of different concentrations of silver nitrate and silver thiosulfate on the fruit of strongly female seed melon were studied,by increasing the concentration of silver nitrate and silver thiosulfate,the single seed number and single fruit weight of seed melon showed a decreasing trend,while the proportion of mutated malformed fruit gradually increased.High concentrations of silver nitrate and silver thiosulfate are not conducive to the growth of seedmelons.(3)In the F2 generation,the normal plant tree:the number of predominately gynoecious plants=3:1;when f1 is backcrossed with the predominately gynoecious plants,the normal plant tree:the number of predominately gynoecious plants=1:1;F1 when backcrossing with normal plants,there is no production of predominately gynoecious plants in the offspring.It can be concluded that the predominately gynoecious trait of edible seed watermelon is controlled by a recessive gene and satisfies the Mendelian separation law.