萝卜游离小孢子培养及胚再生植株研究

目的]探讨在自然生长条件下若干因素对萝卜（RaphanussativusL．）小孢子胚诱导及胚再生植株的影响。方法]首先探讨不同萝卜品种的出胚能力，然后分析热激、低温预处理和培养基对小孢子培养的影响，最后研究胚状体再生成苗与植株继代培养情况。结果]对22份萝卜材料进行游离小孢子培养，12份获得胚状体，3份获得再生植株，出胚材料中90％以上为杂种一代。4℃低温预处理0～3d小孢子出胚率无明显差异；培养基中加入1～2滴0．5％活性炭和一定浓度6-BA可显著促进小孢子诱导产生胚；不同萝卜品种适宜的热激温度和时间有所不同；发育正常的子叶型胚成苗率为100％；胚萌发分化早期适宜培养基为B5＋2％蔗糖＋1．2％琼脂，后期可逐渐将琼脂浓度降低；FCM测定小孢子植株自然加倍率为30％，单倍体占少数，四倍体与嵌合体（二、四倍）均为30％；秋水仙素处理单倍体植株，人工加倍率达60％。结论]该研究完善了萝卜游离小孢子培养技术，可提高单倍体获得频率，加快这一技术在育种实践中的应用步伐。

Study of Isolated Microspore Culture and Plant Regeneration from Embryoid of Radish（Raphanus sativus L. ）

Objective ] The aim was to discuss the effects of several factors on embryoid !nducement from microspore and plant regeneration from embryoid of radish under natural conditions. Method] Firstly, the ability of embryos of different radish cuhivars were discussed, secondly, the effects of heat-shock, low temperature and medium on microspore culture were analyzed, thirdly, the status of embryoid regeneration from micro- spore and then converting into plant, and plant subculture were studied. Result] 22 varieties of radish were tested in isolated microspore culture. 12 genotypes got embryoids successfully and 3 got regeneration plants. More than 90% of embryonic materials were hybrids. There was no signifi- cant difference in the embryoid yield after pretreatment at 4 ~C low-temperature for 0 - 3 days ; the supplement of 1 - 2 drops of 0.5% activated charcoal（AC） and 6-BA to NLN initiated embryogenesis significantly; different temperature and time for heat- shock were suitable for different radish varieties ; the regenerated ratio of healthy embryoids reached 100% ; the suitable medium might be B5 ＋ 2% sucrose ＋ 1.2% agar for em- bryoid germination and differentiation early, and the agar concentration should be gradually reduced later; the proportion of diploids was 30%, a few were haploids, and tetraploids and mixoploids （diploid and tetraploid）were also 30% ; the rate of artificial doubling was 60%. Conclusion ] The study completes isolated mierospore cultivation technique of radish, which improves improve the rate of obtaining haploid, then speed up this technique＇ s application step in breeding practice.