Genic interaction between rp(t) and nl1

10.Genic interaction between ip(t) and nil T. Aida1,2 and I. TAKAMURE1 1) Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589 Japan 2) Present address: 5-24, Okoji-cho, Sendai, Kagoshima, 895-8650 Japan In the retarded panicle rp(t) mutant, the development of panicles is inhibited under low temperature condition (Aida et al. 1995). Under the low temperature condition, panicles of the rp(t) mutant remain in a juvenile stage without spikelet formation and are covered with bract hairs. In contrast, the rp(t) mutant develops nearly normal panicles and spikelets with low seed setting under the high temperature condition. The neckleaf (nil) mutant has a bract leaf at the neck node of panicle (Nagao & Takahashi 1963). Usually the large part of nil panicle is enclosed by the bract leaf. In this report, we examined the genic interaction between rp(t) and nil. The F2 population of the cross between rp(t) and nil was grown in the paddy field of the experimental farm, Hokkaido University. This F2 population segregated into the ratio of 9 normal: 3 rp(t): 3 nil: 1 rp(t) nil (Table 1 and Fig. 1). F3 progeny lines derived from 11 nIl plants of the F2 population were grown in the paddy field. In eight lines, the ratio of 3 nil: 1 rp(t) nil was observed. In other three lines, all plants were nil types. Character expression was compared among four phenotypes which segregated in F2 population of the cross, rp(t) x nil. The double mutants showed more than 10 leaves at nodes of a panicle, few reduced spikelets without floral organ and complete sterility (Table 2). It seems that the interaction between rp (t) and nil inhibits the differentiation of floral organs maintaining the vegetative growth during the panicle development. References Aida, T., I. Takamure and T. Kinoshita, 1995. Inheritance of a physiological mutant showing retarded panicle development. RGN 12:202-203. Nagao, S. and M. Takahashi, 1963. Trial construction of twelve linkage groups in Japanese rice. -Genetical studies on rice plant, XXVII- J. Fac. Agr. Hokkaido Univ. 53: 72-130.

10.Genic interaction between ip(t) and nil

T. Aida1,2 and I. TAKAMURE1

1) Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589 Japan

2) Present address: 5-24, Okoji-cho, Sendai, Kagoshima, 895-8650 Japan

In the retarded panicle rp(t) mutant, the development of panicles is inhibited under low temperature condition (Aida et al. 1995). Under the low temperature condition, panicles of the rp(t) mutant remain in a juvenile stage without spikelet formation and are covered with bract hairs. In contrast, the rp(t) mutant develops nearly normal panicles and spikelets with low seed setting under the high temperature condition. The neckleaf (nil) mutant has a bract leaf at the neck node of panicle (Nagao & Takahashi 1963). Usually the large part of nil panicle is enclosed by the bract leaf. In this report, we examined the genic interaction between rp(t) and nil.

The F2 population of the cross between rp(t) and nil was grown in the paddy field of the experimental farm, Hokkaido University. This F2 population segregated into the ratio of 9 normal: 3 rp(t): 3 nil: 1 rp(t) nil (Table 1 and Fig. 1). F3 progeny lines derived from 11 nIl plants of the F2 population were grown in the paddy field. In eight lines, the ratio of 3 nil: 1 rp(t) nil was observed. In other three lines, all plants were nil types.

Character expression was compared among four phenotypes which segregated in F2 population of the cross, rp(t) x nil. The double mutants showed more than 10 leaves at nodes of a panicle, few reduced spikelets without floral organ and complete sterility (Table 2). It seems that the interaction between rp (t) and nil inhibits the differentiation of floral organs maintaining the vegetative growth during the panicle development.

References

Aida, T., I. Takamure and T. Kinoshita, 1995. Inheritance of a physiological mutant showing retarded panicle development. RGN 12:202-203.

Nagao, S. and M. Takahashi, 1963. Trial construction of twelve linkage groups in Japanese rice. -Genetical studies on rice plant, XXVII- J. Fac. Agr. Hokkaido Univ. 53: 72-130.