在控制条件下光敏核雄性不育粳稻抽穗与结实的光周期与温度反应特性

Heading and Seed Setting of japonica "Genie Male--Sterile Rice" (GMSR ) Under Different Photoperiods and Temperatures in Phytotron

在人工气候室研究了１５个光敏核雄性不育系粳稻抽穗与结实对日长与温度的反应特性。１个品系抽穗的光周期反应极弱，８个中等；６个强；农垦５８Ｓ与其原种反应均强．但ＰＳＰ略有差异；而且农垦５８Ｓ在雌雄蕊原基分化前移入ＬＤ，不但抽穗延迟且结实率显著降低，而农垦５８抽穗虽延迟但结实正常。高温抽穗促进车品系间差异大，从０～４ｄ．９％，较多为２２％～３８％。１５个不育结实的光周期反应明显；它们在高温、低温、ＬＤ下结实明显受阻，有的即使在ＳＤ下结实率亦很低。说明它们雄性细胞较孱弱易受不良光、温条件危害，可能是遗传上有缺陷；繁种时应注意地区的光、温条件，并利用ＳＤ下结实尚可的品系。

Heading and seed setting of 15lines of GMSRs and their ancester variety Nongken 58 of Oryza Sativa subsp.japonica were investigated in phytotronby four combinations of temperaturesand photoperiods: (A) 25 ℃ 12 h illumination (SD); (B) 25 ℃ 15 h(LD); (C) 30 ℃ 1 12 h (HT); (D)20℃ 12 h (LT).Most of the GMSRs tested wereresPOnsive to SD, but their sensitivitydiffered markedly. Only one line(CG17S) showed very weak sensitivity to SD, with a photoperiod sensitivePeriod (PSP) of 1 day. The other 8medium maturing lines with a PSP of13 -- 47 days, and 5 late mafuringlines with a PSP of 64 -- 1 10 days.The late line of N90445 is very exacting, for only a few plants headed under LD even at the end of the experiments (327 days after seedling). Asregards to PSP, there is no significantdifference between the GMSR lineNongken 585 and its ancestor lineNongken 58. When the heading Periods of 20 ℃, 25 ℃, and 30 ℃ treatments were compared, the headingdate of most GMSRs tested was eariestat 25 ℃, but M105--9S, 70015,N50885 headed earliest at 30 ℃ Theenhancement of the photoperiod resPOnse by higher temperature (25 ℃ or30 ℃ ) was very prounonunced in 13lines, the maximum temperature sensitive rate (TSR ) being 44. 9%(7001S) higher than the 20℃ (Table1 ).In contrast to the ancestor varietyNongken 58 the fertility of thesejaponica GMSRs was very sensitive toLD. As the P8nicles of the lines tested,which were cultivated in LD or transferred into LD before anther primordium differentiation, were completely ornearly completely sterile (Table 2,3). The data also showed that underLD, the seed setting rate of these GMSRs declined markedly, ranging from0 to 6. 2% (Table 2). However, it isevident that HT (30 ℃ ) or LT(20℃ ) also adversely affected seedsetting. Statisticalanalysis of the variance of the seed setting rates of theseGMSRs showed that the differencescaused by LD as well as HT of LTtreatment were very significant (at0. 01 level using u-test) or significant(at 0. 5 level) as comPared with thecontrol (25 ℃ 12 h ilumination). Although 7001S, N50885, N90445showed no difference caused by LT,and S8 caused by LD. And it is interesting to note that seed setting rates ofsome lines such as CG17S, LS2,64JS) S8 and WDI--S and were verylow either in SD or LD and under HTor LT. So it is not6worthy that theselines need be further improved for seedproduction in hybrid rice breeding.