以組織培養法挽救Cajanus cajan (L) Millspaugh×Cajanus platycarpus (Benth.) van der Maesen之雜種胚

Rescue of Cajanus cajan (L) Millspaugh × Cajanus platycarpus (Benth.) van der Maesen Hybrid through Embryo Culture

由於Cajanus cajan和Cajanus platycarpus這兩種豆科植物在交配後，其雜種胚胎在發育過程中會發生合子後不親合（post-zygotic）障礙，所以無法利用傳統育種方法將同屬之野生種的基因轉入Cajanus cajan而達到改善遺傳性狀的目的。本文利用離體（in vitro）胚培養技術能夠成功地拯救在生體中（in vivo）命定會夭折的雜種胚。取11至15天大的雜種胚進行培養，不論是在MS或B5基本培養基中加入不同之2,4D/IAA和kinetin組合的條件下，均只能得到不分化的癒傷組織；而16至20天大的胚則可在含1.0mgL-1 IAA+ 0.5/1.0mgL-1 Kinetin的MS或B5培養基上，成功地發育成小苗。由此得知，挽救雜種胚的成功，除了賀爾蒙的濃度與組合有影響外，主要乃取決於外植體的胚齡大小。

Genetic improvement of Cajanus cajan (L.) Millspaugh through gene introgression involving wild species of the genus using conventional methods is hampered due to the prevailing post-zygotic barriers. An in vitro technique has been used for rescuing the hybrid embryos between C. cajan and C. platycarpus, that are otherwise destined to abort under in vivo conditions. 11 to 15 days old embryos developed into only undifferentiated callus on both MS and B5 medium supplemented with 2,4-D/IAA alone and in combination with Kinetin. On the other hand, 16-20 days old embryos could be successfully rescued on MS/B5 + 1.0 mgL-1 IAA + 0.5 or 1.0 mgL-1 Kinetin. Successful embryo rescue operation is largely governed by age of the explant, apart from other decisive factors like hormonal combinations and their concentrations in the culture medium.