Abstract: Cold stress is a significant problem for rice production in temperate or tropical regions，which often result in poor stand establishment，delayed growth，and non- uniform maturation．Choosing rice seedling with cold tol- erance earlier and accurately is especially important in rice production systems，which are becoming more wide- spread．To elucidate the growth characteristics of precision hill- drop drilling rice at seedling stage under low temper- ature stress，a pot experiment was conducted using super hybrid rice variety,Peizataifeng，cultivated in light incuba- tor under five different temperature treatments．The five temperature treatments were 9，11，13，15，25 ℃ (taken as control，CK)，respectively．Effects on plant height，leaf area，leaf dry weight，stem dry weight and total dry weight， root morphological traits (including root / shoot ratio，length，surface area，average diameter，root volume) and antiox- idant enzyme activities of rice seedlings were determined to better understand potential mechanisms for cold toler- ance．Antioxidant enzyme activities were proline content，superoxide dismutase，catalase and peroxidase activities， respectively．Root morphological traits were measured using Win RHIZO root analysing system．Results by means of anova analysis and principal component analysis showed that plant height，leaf area，leaf dry weight，stem dry weight and total dry weight of rice seedlings were significantly decreased under the low temperature treatments，compared with the control treatment．However，root / shoot ratio，proline content，superoxide dismutase catalase and peroxidase activities were significantly increased under low temperature stress．At seedling stage，heavier leaf dry weight and to- tal plant dry weight and higher specific leaf weight (heavier leaf dry weight and smaller leaf area) and taller plant height may be considered as strong adaptability to cold stress rapidly and accurately．

Key words: Low temperature, Precision hill- drop drilling, Rice, Growth characteristics

CLC Number: 

• S511.01