【作者】 刘化龙；

【导师】 邹德堂；

【作者基本信息】 东北农业大学 ， 作物遗传育种， 2005， 硕士

【摘要】 本试验采用75个寒地粳稻品种(系),研究了品种(系)间发芽期耐冷性、芽期耐冷性、春川冷水池内低温直播成苗情况及成熟期冷害的差异。对品种间不同时期的耐冷性进行综合分析,从中筛选适合寒地生态条件下直播的品种。试验结果如下: 10℃低温和25℃常温条件下发芽势、发芽率、发芽系数、平均发芽天数及萌发指数品种间差异极显著,变异系数大小顺序为:10℃发芽系数>25℃平均发芽天数>10℃平均发芽天数>25℃发芽系数>10℃发芽势>10℃发芽率>25℃发芽势>25℃发芽率,根据萌发指数反应了在10℃低温与25℃常温下品种萌发速度及萌发数量的不同,把供试品种分为敏感型、中间型和抗冷型。10℃低温发芽势、发芽率、发芽系数呈极显著的正相关,而它们与平均发芽天数呈极显著负相关。25℃常温发芽系数与10℃低温的发芽势、发芽率、发芽系数和25℃发芽势呈极显著正相关,而与10℃平均发芽天数呈极显著负相关。10℃低温萌发指数与10℃低温发芽势、发芽率、发芽系数及25℃常温发芽系数、25℃萌发指数呈极显著正相关,而与平均发芽天数呈极显著负相关。萌发指数下降值与平均发芽天数呈极显著正相关,而与发芽势、发芽系数及10℃低温萌发指数呈极显著负相关。 对粳稻种质资源在低温条件下发芽期、芽期和采用春川冷水池的直播成苗情况进行主成分分析,根据入选的特征根和相应的特征向量及各性状经标准化的主成分得分值,进一步算出75个品种的3个主成分得分。入选的3个主成分能较好地代替不同种质发芽期、芽期、直播成苗期的各个耐冷指标,进而对其耐冷性进行综合评价。第一主成分大的品种低温发芽能力强,适合低温直播对品种的要求。第二主成分大的品种芽期耐冷试验表现死苗数多和低温直播出苗数少,导致低温条件发芽势、发芽率、发芽系数及萌发指数也降低。第三主成分大的品种25℃常温下平均发芽天数多,低温直播出苗数少,导致10℃低温发芽势、发芽率和发芽系数也降低。根据三个主成分得分筛选出14个综合耐冷特性较好的品种。在供试品种中单一时期耐冷特性较好的品种较多,各个生育时期耐冷性均好的品种较少。因此,只要把现有品种(系)各个时期耐冷特性加以改良或将分散在一些品种资源中的优良耐冷性状综合起来,更多还原

【Abstract】 With 75 varieties (or lines) of japonica studying on cold tolerance at sprout stage, bud stage and simulate seedling emergence under low temperature direct sowing and the difference caused by cold among the varities at mature stage.Combinning the cold tolerance of varities at different growth period to reflect the need of germplasm resources that fitting for the direct sowing under cold region. The results were as follow:It exist most significantly difference between varieties in germinability, germination rate .germination coefficient, sprouting days and sprouting index at 10℃ and 25℃.The order of coefficient of variation from big to small were as follow.germination coefficient under 10℃ >average sprouting days under 25℃> average sprouting days under 10℃>germination coefficient under 25℃>germinability under 10℃>germination percentage under 10℃>germinability under 25 ℃>germination percentage under 10℃. Based on the sprouting index that reflected sprouting speed and sprouting numbers under 10℃ and 25℃, the tested varieties can be divided to sensitive type, middle type and cold tolerance type. It is very significantly positive correlation between the germinability .germination percentage and germination coefficient under 10℃, but they were very significantly negative correlation with average sprouting days. Germination coefficient under 25℃ was significantly positively correlated with germinability under 10℃ and germinability under 25 ℃, but negative correlated with average sprouting days under 10℃. Sprouting index under 10 ℃ was very significantly correlated with germinability under 10℃, germination percentage under 10 ℃, germination coefficient under 10 ℃, germination coefficient under 25 ℃ and sprouting index under 25 ℃, but very significantly negative correlation with average sprouting days.The descending value of sprouting index was very significantly positive correlation with average sprouting days and was very significantly negative correlation with germinability, germination coefficient and sprouting index under 10℃.According to choosed characteristic root, characteristic vecter and standard genotype value of each traits resources of japonica at sprouting stage, bud stage and the condition of simulating direct sowing under low temperature, we calculated 3 major components of 75 varieties. The choosed 3 major components can well evaluate cold tolerance instead of criteria of cold tolerance for different germplasm resource at sprouting stage ,bud stage and seedling stage of direct sowing .The varietieswhich have a big value for first major component have a strong sprouting capacity ,so it is suitable for the demand of direct sowing under low temperature .The varieties which have a big value for second major component showing lots of died seedless and fewer seedling emergence under low temperature in the experiment of varieties’ cold tolerance, result in a decendence of germinability termination percentage .germination coefficient and sprouting index. The varieties who have a big value for third major component have lots of average sprouting days under 25 °C general temperature and fewer seedling emergence under low temperature direct sowing , result to a descendent of germinability , germination percentage and germination coefficient. According to the same demand of three major components, we choosed 14 varieties which have better cold tolerance, lots of varieties have cold tolerance in single stage and fewer varies have a better cold tolerance in every stage.There are great damage among the varities between cool-summer damage due to delayed growth and cool-summer damage due to impotency at rice growth period.75 tested varities were irrigated with cold water, in which 85% among the varities have more than 50% germination percentage. According to the grades of reproductive index, evaluation showed that all tested varieties have a stronger cold tolerance at booting stage. But the investigation result at booting emergence showed that date of booting emergence had a clearly delay after treatment and the difference is notable in different varieties. Tested material have strong cold tolerance to cold damage at booting stage,but the varieties which have weak cold tolerance is more sensitive.all the tested varities were deeply irrigated for a long time with cold water at growth period,which is mostly sensitive for low temperature at late booting stage ,but is not sensitive at booting stage.the booting emergence of irrigating deeply for a long time.the booting emergence of irrigating deeply for a long time which cold water is not noticablly delayed when it was compare to the period of booting stage.更多还原