辐射花粉授粉培育单倍体黄瓜研究

Studies on Induction of Haploid Cucumbers by Irradiated Pollen Pollination and Their Characterization

【目的】为系统探讨授粉组合、雄花辐射时的发育时期和辐射剂量对黄瓜座果和单倍体胚生产的影响。【方法】选用了32个不同基因型黄瓜作为母本,6个不同基因型黄瓜作为父本,采用1次辐射2次授粉结合胚胎拯救的方法。【结果】从15个基因型的母本中获得了单倍体胚48个,单倍体胚的平均产率为0.77%,最高产率可达50.00%。【结论】试验发现雄花辐射时的发育时期对座果率影响不大,对单倍体胚产率有一定影响;辐射剂量的差异对座果率和单倍体胚产率都有影响,但剂量效应不明显;授粉组合之间单倍体胚产率差异很大。对单倍体的形态、减数分裂染色体行为与育性、部分生理生化指标进行了研究,结果表明单倍体的茎叶表面形态和花器官形态与二倍体存在显著的差别;大部分的单倍体植株雌雄均不育,但单倍体H2的雌雄配子均有一定育性;对减数分裂行为的观察发现单倍体H2的各个分裂时期的染色体行为均异常,但后期I极低频率的(0+7)型分离方式可能产生具有育性的配子;单倍体的叶绿素含量、过氧化物酶活性(POD)及可溶性蛋白含量与二倍体存在较大差异。

[Objective] The aim of the experiment is to systematically investigate the effects of pollination combination, development stage of male flower when subjected to irradiation and the dosage on fruit setting and haploid production of cucumber. [Method] The methods of irradiated once and pollinated twice plus embryo culture were adopted, 32 different genotypes of cucumber were used as maternal parents and 6 genotypes were used as paternal parents to produce haploid cucumber through γ-irradiated pollen pollination. [Result] Totally 48 haploid embryos were successfully recovered from 15 genotypes, and the average percentage of haploid embryo production was 0.77% and the highest was 50.00%. [ Conclusion] No significant influence of male flowers developing stage on fruit setting was found but the haploid embryo production was affected. The irradiation dosage affected fruit setting and haploid embryo production, but there was no significance. The haploid embryo production was affected greatly by different pollination combinations. The experiments from morphological observation, meiotic chromosome behavior and fertility investigation, and some physiological and biochemical measurements indicated that there were significant morphological differences between haploid and diploid. Most haploid plants had no fertility except H2. Meiotic observation on the H2 found the abnormal behavior at every stage, but there was a production of 0＋7 gametes produced at very low frequency at anaphase Ⅰ, which likely produced the fertile gametes. Differences in chlorophyll contents, activation of POD, soluble protein contents were found between haploid and diploid plants.