西葫芦未受精胚珠离体培养条件的优化及胚囊植株的产生

Improved Conditions of in vitro Culture of Unpollinated Ovules and Production of Embryonary Sac Plants in Summer Squash(Cucurbita pepo L.)

目的建立西葫芦离体雌核发育高频植株再生体系,以加速自交系选育,有效缩短西葫芦杂种一代育种周期。方法将西葫芦未受精胚珠接种至附加2,4-D、NAA、BA的N6培养基上可形成胚状体,该胚状体转接至无激素的N6培养基上可形成再生植株。结果试验共获得120棵再生植株(R0),其中41株因生活力低下死亡,8株用于摸索移栽方法死亡,71株移栽成活且生长正常,其中42株性状表现符合二倍体特征且育性正常,已有10株获得自交果实及种子,其余29株育性异常。试验结果表明,胚珠发育时期、培养基、供体基因型及供体栽培季节等均显著影响胚状体诱导频率。结论胚状体起源于胚囊成员细胞,再生植株为胚囊植株。试验筛选出3种诱导频率较高的培养基;以开花前1日及当日的胚珠诱导频率较高;秋播材料诱导效果最好。

[Objective]The aim of this research was to establish a high frequency plants regemeration system for summer squash （Cucurbita pepo L.） via in vitro gynogensis, in order to provide a quick way to abtain self-bred lines for summer squash F1 breeding. [Method] Unpollinated ovules from summer squash ovaries were cultured on N6 medium and supplemented with 2, 4-D, NAA, BA. After the embryoids were obtained, they were transplanted into N6 medium without growth regulators, and the regenerated plants would be obtained. [Result] 120 embryonary sac plants were regenerated in this research. Among them, 41 plants were died of reduced growth, 8 plants died of studying the regenerated method, 71 plants survived after transplanting into soil. In these survived plants, 42 have normal fertility and 10 of them had obtained self-bred fruits and seeds; 29 have abnormal fertility. The statistical results showed that ovules development stage, medium, material genetype and material planting season had significant effects on the embryoids inductivities. [ Conclusion ] The embryoids came from the cells of embryonary sac, the regenerated plants are embryonary sac plants. 3 mediums had been selected for high inducticities. Ovules from one day before anthesis and the day of anthesis had higher inducticities and the materials planted in autumn was the best for induction of embryoids.