Study On Culture In Vitro Of Unfertilized Ovule And Un-pollinated Ovary In Watermelon

In order to obtain the optimum culture condition of un-pollinated ovary and unfertilized ovule to induce haploid in Watermelon, his paper has selected four diverse genotypes of watermelons. as text materials, with XiNong9and MiGui as the object to study the unfertilized ovules, as well as with ZaoChunHongYu,XiNong9and XiaoLvHang as the target to research the un-pollinated ovary, which has studied several influencing factors of Watermelon in vitro gynogenesis, such as heat shock treatment of donor plants in dark, genotype, different sampling time, pretreatment of explants,2,4-D concentration and combinations of various hormone concentration. The results are as follows:1. Culture in vitro of un-pollinated ovary and unfertilized ovule in Watermelon needs to be disposed with heat shock treatment in dark. Culture in vitro of XiNong9un-pollinated ovary has the highest induction rate under33℃for3days, but proved to have no great difference from those under33℃for4days. It also shows that heat shock treatment in dark under33℃for4days is conducive to activate female nucleus in XiNong9ovule culture, as well as culture in vitro of other ovule and ovary. Generally, heat shock treatment in dark under33℃for4days is the best for culture in vitro of un-pollinated ovary and unfertilized ovule in Watermelon.2.Genotype has played an important role in culture in vitro of unfertilized ovule and un-pollinated ovary in Watermelon.Culture in vitro of un-pollinated ovary and unfertilized ovule in Watermelon has tested on three kinds of genotype, showing that zaochunhongyu can get regeneration plant while the other two genotypes fail to differentiate young plants, and also culture in vitro of unfertilized ovule can’t obtain regeneration plants, but the buds rate are very different, which proves that genotype and cultivating method have played a key role in inducing haploid in vitro.3.Sampling time also exert some influence on haploid induction. The test indicates that the un-pollinated ovary of the-day-before blossom has much higher inductivity than both those of two-day-before blossom and those of that-day blossom. The highest bud rates of zaochunhongyu, xinong9and xiaolvhuang are17.2%,16.1%,3.3%respectively.4. Pretreatment before sampling can quickly picked up the complete ovule culture in vitro.The inductivity of unfertilized ovules under CPPU treatment is higher than those under mentor experiment and Anti-pollination treatment. The highest bud rates of Xinong9and migui are15.6%、4.0%respectively.5.2,4-D concentration influence on watermelon vitro Gynogenesis.2,4-D is is an indispensable plant hormone in vitro Gynogenesis of watermelon, which has different influence on various genotypes. According, to selected materials, concentrations are specifically chosen in experiments, and combinations of various concentration are also texted. It reveals that the inductivity of zaochunhongyu hit the highest level when the concentration of2,4-D is3.0-4.0mg.L-1, so does the inductivity of xinong9and xiaolvhuang when the concentration of2,4-D is3.0-5.0mg.L-1. Zaochunhongyu. The best hormone combination for ZaoChunHongYu is4.0mg.L-12,4-D+2.0mg.L-16-BA+0.5mg.L-1NAA and its highest buds rate is15.0%, while the best one for xinong9and xiaolvhuang is3.0mg.L-12,4-D-+2.0mg.L-16-BA+0.5mg.L-1NAA and their highest buds rate arel5.0%and4.3%repetitively. In the culture in vitro of unfertilized ovules, xinong9has the highest inductivity under the concentration of1.5-2.5mg.L-1, so does migui under the concentration of3.0mg.L-1and3.5mg.L-1, and xinon9under the hormone combinations of2.0mg.L-12,4-D+1.0mg.L-16-BA+0.5mg.L-1NAA has the highest inductivity of13.3%. The maximum induction rate of Migui under the concentration of3.5mg.L-12,4-D+1.0mg.L-16-BA+0.5mg.L-1NAA,3.5mg.L-12,4-D+1.0mg.L-16-BA+0.2mg.L-1NAA,3.0mg.L-12,4-D+1.0mg.L-16-BA+0.5mg.L-1NAA is6.7%.6.Regeneration medium can promote buds further differentiation to complete plants. Induction rate reached best level is0.5mg.L-16-BA+0.1mg.L-1NAA.7.Root induction:In the MS medium can induction root grow by adding0.1mg.L-1NAA and0.1mg.L-1IBA.The one added with0.1mg.L-1NAA can make the root grow quickly, which can induce plenty of root, while the one added with O.1mg.L-1can generate better roots than NAA.8.Ploidy identification:According to the quantity of chromosome in root cells of regeneration plants, haploid,diploid and tetraploid in regeneration plants can be identified.