耐贮水稻种质资源的筛选及生理特性

  目的  水稻Oryza sativa种子的耐贮性是与种用价值、种源和粮食安全密切相关的重要性状。研究水稻种子耐贮特性，对水稻种质资源保存以及保障国家粮食安全具有重要意义。  方法  基于220份水稻品种，经过5~6 a的自然老化，通过室内标准发芽实验筛选出耐贮水稻品种，并进一步测定不同耐贮品种间的生理特性。  结果  随着自然老化时间的延长，不同水稻品种的发芽率和发芽势均呈现逐步降低的趋势。与种子初始质量相比，常规粳稻、常规籼稻、杂交稻的发芽率平均降低了62.2%、23.4%、45.3%；发芽势平均降低了55.0%、38.1%、50.7%。以发芽率下降幅度＜5%且发芽势下降幅度＜15%作为耐贮品种的评价标准，筛选出以‘南粳44’‘Nanjing 44’、‘沈稻18’‘Shendao 18’、‘天稻丰’‘Tiandaofeng’为代表的耐贮常规粳稻；‘赣晚籼35号’‘Ganwanxian 35’、‘赣晚糯7号’‘Ganwannuo 7’、‘甬籼69’‘Yongxian 69’为代表的耐贮常规籼稻；‘两优培九’‘Liangyou Peijiu’、‘中浙优1号’‘Zhongzheyou 1’、‘晶两优华占’‘Jingliangyou Huazhan’为代表的耐贮杂交稻。进一步研究发现:以上9个品种具有淀粉酶活性高、抗氧化酶活性高、脯氨酸质量分数高、丙二醛质量摩尔浓度低的特点。  结论  基于耐贮能力与生理特性，推荐‘南粳44’‘沈稻18’‘天稻丰’‘赣晚籼35号’‘赣晚糯7号’‘甬籼69’‘两优培九’‘中浙优1号’‘晶两优华占’等为耐贮种质，这为今后选育耐贮藏的水稻优良品种提供了新资源。图2表6参40

Screening and physiological characteristics of storable Oryza sativa germplasm resources

  Objective  This study, with an investigation of the seed storability, an important trait closely related to seed value, provenance and food security, of rice (Oryza sativa), is aimed to survey the storability characteristics of rice seeds so as to promote the conservation of rice germplasm resources and the protection of national food security.  Method  Based on 220 rice cultivars, after 5?6 years of natural aging, rice varieties with good storage tolerance were selected employing laboratory standard germination experiment before the physiological characteristics of different cultivars were determined.  Result   (1) With the prolongation of natural aging time, the germination rate and germination potential of different rice cultivars showed a trend of gradual decrease. (2) Compared with the initial seed quality, the germination rates of conventional japonica rice, conventional indica rice and hybrid rice decreased by 62.2%, 23.4% and 45.3% on average, respectively whereas the germination potential decreased by 55.0%, 38.1% and 50.7% on average. (3) Based on the evaluation criteria (varies with a decrease in germination rate ＜5% and a decrease in germination potential ＜15% are regarded as storable cultivars), storable conventional japonica rice represented by ‘Nanjing 44’ ‘Shendao 18’ and ‘Tiandaofeng’ were screened out along with storable conventional indica rice represented by ‘Wanxian 35’ ‘Ganwannuo 7’ and ‘Yongxian 69’; the storable hybrid rice represented by ‘Liangyoupeijiu’ ‘Zhongzheyou 1’ and ‘Jingliangyou Huazhan’. (4) It was further found that ‘Nanjing 44’ ‘Shendao 18’ ‘Tiandaofeng’ ‘Ganwanxian 35’ ‘Ganwanuo 7’ ‘Yongxian 69’ ‘Liangyou Peijiu’ ‘Zhongzhenyou 1’ and ‘Jingliangyou Huazhan’ had the characteristics of high amylase activity, high antioxidant enzyme activity, high proline content and low MDA content.   Conclusion  In terms of the storability and physiological characteristics, ‘Nanjing 44’ ‘Shendao 18’ ‘Tiandaofeng’ ‘Ganwanxian 35’ ‘Ganwannuo 7’ ‘Yongxian 69’ ‘Liangyoupeijiu’ ‘Zhongzheyou 1’ ‘Jingliangyou Huazhan’ are recommended and storable germplasms, providing new resources for the future selection of rice cultivars with storage tolerance. Ch, 2 fig. 6 tab. 40 ref.]