| In this paper, 9 newly developed indica photo-thermo-sensitive genic male sterile lines (PTGMS) and Pei'ai64S (ck), one of the most popular indica PTGMS in two-line hybrid rice breeding in China, were used to study the characteristics of the response to temperature and day length, the sterile stability, the sterile alteration, the main agronomic traits, stigma vitality, combining ability and heritability were systematically studied as well, on the purpose of evaluating their breeding value in Jiangsu Province. The results were summarized as follows:1. Agronomic Traits(1) Compared with Pei'ai64S (ck), one of the elite PTGMS, the 9 sterile lines belonged to midripening indica rice, however, 208S and XuxuanS belonged to early midripening indica rice, while Y3 was a late one. GD-8S, GD-7S, 02-142, W9593S, YW-2S and Shuguang582S, including Pei'ai64S (ck), belonged to midripening indica rice. The sensitivity to light and temperature of those sterile lines were closed to Pei'ai64S (ck) except for Y3, originated from Liaoling province, which showed more sensitive to light than temperature.(2) The plant height of those sterile lines ranged from 64.8 to 92.8cm. As forpanicles per plant, there are 7 sterile lines obviously exceed to Pei'ai64S (ck), which showed that the tillering ability of newly-developed sterile lines were greatly improved.(3) Of all 10 PTGMS, the closure of panicle in Shuguang582S, GD-7S and W9593S were significantly less than Pei'ai64S (ck). There are significantly difference in sensitive to GA3 in all 10 PTGMS, the enclosure of panicle in XuxuanS and 208S were most effective by the use of GA3, then Shuguang582S and Pei'ai64S (ck).(4) The stigma vitality of the new PTGMS was strongest on the exactly flowering day, came up to 44.5 %~ 86.0%, and there were considerable vitality after flowering 2-4 days; Of all ten PTGMS, the stigma vitality of Shuguang582S, GD-8S, XuxuanS, Y3 and 208S were stronger than Pei'ai64S (ck), while GD-7S, 02-142, W9593S, and YW-2S were less strong than Pei'ai64S (ck).(5 ) With the 4 indica /japonica test variety identified, 02-142 and Pei'ai64S (ck) were concluded as wide-compatibility lines.2 Characterization of Fertility Alteration(1) On the base of bagged self-pollination, the fertility of the sterile lines were classified into three types as complete sterile(<0.5%), partial fertile(0.5~10%) and fertile(>10%). All Of 10 tested sterile lines showed completely sterile in the period from late July to early September. The stable sterile periods of GD-8S, Pei'ai64S (ck), XuxuanS, 02-142 and 208S in Nanjing region were longer than 30 days, and the rest lines were longer than 20 days.(2) GD-8S, XuxuanS and Y3 showed relatively shorter fertility alteration stage and longer fertility stage, those sterile lines can reproduce themselves in Naning in Autumn; GD-7S and YW-2S showed too short fertility stage, so reproduce themselves in Naning for favorable yield might be difficult; while Shuguang582S, W9593S, 208S,02-142 and Pei'ai64S (ck) have no fertility stage in Naning, therefore they must reproduce themselves in another suitable growth region for higher yield.(3) Time sequencing correlation analysis between pollen fertility, daily mean temperature and day length of 25-5d before heading indicated that all 10 sterile lines were sensitive to day length and temperature. XuxuanS, 02-142 and Pei'ai64S (ck) were sensitive to daily mean temperature of 25-5d before heading; YW-2S, W9593S, GD-8S and 208S were sensitive to daily mean temperature of about 20-5d before heading; while Y3, GD-7S and Shuguang582S were 25-10d before heading.(4 ) The relationship between pollen fertility, daily mean temperature and day length during sensitive time were accorded with equation of curvilinear regression of second degree in suitable range. On the base of quadratic curve equation, critical point temperature (CPT) and critical point day length (CPDL) of fertility alteration in 10 PTGMS were estimated. The CPT of 02-142 and Shuguang582S was 22°C and 23.6°C; respectively; while that of XuxuanS, GD-7S,...
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