FAN, SHUGUO*, CHENGYE LIANG, AND HONGXIAN LIU. South China Institute of Botany, Academia Sinica, Guangzhou 510650, P. R. China. - Factors influencing callus inducition and plant regeneration of young panicles in rice (Oryza sativa L.).
Young panicles from 11 rice varieties, Zhenshan 97A (WA type
cytoplasmic male-sterile (CMS) line, indica), Zhenshan 97B (WA type
maintainer line, indica), IR24, IR26, Taiyin 1, Minghui 63 (WA type
restorer line, indica), Hongyuan A (HL type CMS line, indica), Baoyuan
A (BT type CMS line, indica), Nanguangzhan (genic male-sterile (GMS)
line, indica), Nongken 58s (photoperiod-sensitive genic male-sterile
rice (PGMR), japonica) and W6154s (thermosensitive genic male-sterile
rice (TGMR), indica), were cultured on different media. Factors
influencing callus induction and plant regeneration of young panicle
were examined. The main results were as follows: All the explants of
the 11 rice varieties cultured on the media containing 2,4-D could
produce calli. The callus could be induced and the plantlet could be
regenerated on one step culture (without transferring) in young
panicle culture of japonica variety using 2,4-D free medium containing
NAA 2 mg/L and KT 2 mg/L; while the young panicles from indica
varieties showed direct budding and resulting in plantlet formation.
This indicated 2,4-D played an important role in callus induction. KT
inhibited callus induction obviously, but accelerated plant
regeneration of young panicles in indica rice, and had fewer effects
on plant regeneration of japonica rice. NAA 0.2 mg/L and ABA 0.1 mg/L,
mannitol 2% and Vitamin B1 1 mg/L had some effects on callus induction
and differentiation and accelerated callus growth and raised plant
regeneration frequency. Inositol was not essential in media, adding it
was to accelerate the growth of callus. The difference between
male-sterile and fertile varieties on callus induction and plant
regeneration frequency was not significant, even the plant
regeneration frequency of some male-sterile varieties were higher than
that of fertile varieties, viz. CMS had fewer effects on callus
induction and plant regeneration frequency.
Key words: callus induction, in vitro culture, indica, japonica, Oryza sativa L., plant regeneration