Daylength responses of various morphogenetic events after panicle initiation in late japonica rice (Oryza sativa L. ssp. japonica)

Abstract

Plant morphogenesis is an intimate cooperation between environmental signals and a genetically-encoded developmental programme. Although all stages subsequent to floral induction may be influenced by daylength, the information available has come from diverse species during different morphogenetic events. This makes it difficult to investigate how photoperiodic signalling is integrated into various steps of the developmental programme. Here, we report that, in late japonica rice lines, morphogenetic events, including 12th leaf, axis of the main panicle, awn of the glum, anthers, elongation rate of internodes, and pollen fertility of the photoperiod-sensitive genic male-sterile (PGMS) rice, are significantly affected by daylength after panicle initiation. These data indicate that daylength affects many morphologic events, and that changes in morphology are mainly determined by the characteristics of the events themselves. These findings lay a foundation for future investigations into how potentially common photoperiodic signalling system(s) are integrated with diversified developmental events. In addition, we discussed the essential nature of PGMS rice.

Physiological causes of transplantation shock on rice growth inhibition and delayed heading

“…These findings suggested that vegetative growth could proceed relatively well, even when rice plants were grown under short-day conditions at a high temperature if the time of seeding and transplanting of younger seedlings was delayed. Panicle length and the number of grains per panicle increase under short-day conditions [39][40][41] ; however, tillering, which determines the number of panicles, is inhibited under short-day conditions. Consequently, the number of plantings at the transplanting site should be increased to compensate for reduced tillering and ensure that the required number of tillers is produced.…”

Fine Mapping of Two Additive Effect Genes for Awn Development in Rice (Oryza sativa L.)

“…Late japonica rice lines, NK58, NK58s and NK58sr, reportedly showed responses to day length. No awns in panicles were observed under short-day conditions, but under long-day conditions, long awns protruded from the apices of lemmas [ 32 ]. The awns of progeny of the cross SLG × Nipponbare grown in Sanya during the present work were shorter than when the same materials were grown in Beijing.…”