【作者】 石晓云；

【导师】 申书兴；

【作者基本信息】 河北农业大学 ， 蔬菜学， 2003， 硕士

【摘要】 本文对小果型西瓜自交系21，90，141，149，157进行离体组织培养诱导四倍体，研究秋水仙素浓度、处理时间与再生途径对诱导率的影响；西瓜二、四倍体组培苗倍性简易鉴定的方法；聚乙烯醇控制西瓜组培苗玻璃化的适宜浓度；以及激素种类与浓度对组培苗生根的影响。获得以下结果： 1．利用授粉后20～23天的西瓜未成熟胚子叶中部组织离体诱导四倍体，诱导率高，不易产生嵌合体，基因型不同，处理浓度与时间不同，再生途径不同，获得四倍体植株的诱导加倍率也不同。用0.03％～0.07％秋水仙素处理4～9天是适宜的诱导范围，可获得四倍体植株。自交系21，141，149，157经0.05％秋水仙素处理7天可获得的最高加倍率，分别为37％，17％，43％，37％；自交系90经0.03％的秋水仙素处理9天可获得最高加倍率，为50％。通过愈伤组织获得四倍体植株的诱导加倍率高于通过芽丛与单芽的诱导加倍率。 2．利用成熟胚茎尖生长点离体诱导四倍体，秋水仙素浓度为0.05％处理36～48小时是适宜的诱导范围。自交系149处理36小时获最高加倍率为13％；自交系157处理48小时获最高加倍率为17％。 3．西瓜四倍体组培苗与二倍体组培苗相比，植株较矮，叶长宽比变小，气孔变大，气孔密度变小，气孔保卫细胞叶绿体数增多，细胞核直径变大，对玻璃化抗性增强，这些特点可以作为早期倍性鉴定的指标。 4．聚乙烯醇可以有效的控制西瓜二倍体组培苗的玻璃化，适宜的浓度为2.5g／L。 5．IAA、IBA、NAA对西瓜四倍体组培苗都有促进生根的作用，其中IBA的效果最好，适宜的浓度范围为0.2～0.3mg／L；并且接种1～2cm带顶芽的茎段生根时，生根率稳定，根数多，根形态较好，利于移栽。 6．利用田间滴苗法诱导四倍体的加倍率低，经0.2％秋水仙素处理4天后，自交系21，90，141，149，157的加倍率分别为2.8％，0％，5.1％，4.7％，3.2％。更多还原

【Abstract】 Mini-diploid watermelon inbred-line 21, 90, 141, 149, 157 were used for inducing tetraploid in vitro culture. The effect on inducting rate of colchicine concentration and treating time and regenerating way, simple way to identificating ploidy. the optimum concentration of PVA to resist vitreous plantlets, the effect on rooting of hormone varieties and concentration were studied. Conclusions were drawed as followed:1.Middle immature cotylelons in 20 ~ 23 days were used for inducing tetraploid. The inducting rate was high and it was not likely to be mosaic.The doubling rate was different from different genetype , treating concentration and time, regenerating way . Treated by 0.03%~ 0.07% colchicines in 4~9 days was the optimal induction extent. Line 21,90,141,149,157 attained the highest doubling rate, they were 37%,50%,17%,43%,37% respectively. The doubling rate from callus was higher than from buds and crowed buds.2.Mature cotyledon tips were used for inducing tetraploid. When colchicine was 0.05% ,treated in 36~48 hours was the optimal induction extent. The highest doubling rate of line 149,157 was 13%, 17% respectively.3.Watermelon tetraploid plantlets were shorter, leaf lengh to width ratio was smaller, stomas were bigger, density of stoma was smaller, choltoplasts in guard cell were more, diameter of nucleus was longer, the resistance to vitreous plantlets was stronger than that of diploid. They could be used for identificating ploidy early.4.PVA could resist diploid watermelon plantlets to be vitreous , the optimum concentration was 2.5g/L.5.Each of IAA,IBA and NAA could make the tetraploid watermelon plantlets root. IBA was the best.When IBA was 0.2~0.3mg/L , inoculated about l~2cmhigh stem with shoot tip ,the rooting rate , No. of root and morphology of root were good , it was suitable to transplant.6.The doubling rate of seedling dropped was low . When treated by 0.2% colchicines in 4 days , the doubling rate of line 21,90,141,149,157 was 2.8%, 0%, 5.1%, 4.7%, 13.2% respectively. In the first period ,fruit rate and seed rate were very low.更多还原