低温处理对精量穴直播水稻幼苗生长特性的影响

Effects of Low Temperature on Growth Characteristics of Rice Seedlings in Precision Hill-drop Drilling Rice

以超级杂交稻培杂泰丰为材料,采用人工点播的方式模拟机械精量穴直播,利用光照培养箱分别设计4个低温处理(9,11,13,15℃)和一个常温对照(25℃),研究低温处理对精量穴直播水稻幼苗生长特性的影响。方差分析和主成分分析结果表明,低温处理显著降低秧苗的株高、叶面积、叶片干质量、茎鞘干质量和总干质量,然而,却显著增加秧苗根冠比,脯氨酸(Pro)含量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)及过氧化物酶(POD)活性。研究认为,在进行水稻品种的低温适应性评价时,应选择幼苗叶片干质量和植株总干质量比较大,比叶质量大(具有较大的叶干质量和较小的叶面积)及株高较高等形态指标,能够比较准确快捷地反映其低温适应性。

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 tolerance earlier and accurately is especially important in rice production systems,which are becoming more widespread.To elucidate the growth characteristics of precision hill-drop drilling rice at seedling stage under low temperature stress,a pot experiment was conducted using super hybrid rice variety,Peizataifeng,cultivated in light incubator 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 antioxidant enzyme activities of rice seedlings were determined to better understand potential mechanisms for cold tolerance.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 total 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.