温度胁迫对不同烤烟品种幼苗生长及生理指标的影响

为研究温度胁迫对不同烤烟品种幼苗生长及生理指标的影响,进而筛选有效指标比较不同品种抗温度胁迫逆性,采用5真叶期烟草盆栽幼苗为材料,分别对低温、高温胁迫处理10 d后,云烟87、红花大金元和K326品种的叶绿素含量、丙二醛含量、根系活力、硝酸还原酶含量、株高、最大叶长及最大叶宽等指标进行测定。结果表明:(1)低温、高温胁迫后,各品种幼苗的叶绿素、硝酸还原酶含量均下降。(2)丙二醛含量变化表现为:云烟87低温胁迫后显著升高,高温胁迫后差异不显著;红花大金元品种幼苗低温胁迫后与对照差异不显著,高温胁迫后显著升高;K326品种温度胁迫后MDA含量均较对照组显著升高。(3)低温、高温胁迫后,红花大金元、K326品种幼苗的根系活力均较对照组显著下降。(4)形态学指标中,温度胁迫后各品种均有所下降,以K326下降较为显著。(5)红花大金元的抗寒性较强,云烟87次之,K326较差。(6)云烟87的抗高温能力较强,红花大金元次之,K326较差。可见,叶绿素含量、丙二醛含量以及硝酸还原酶是鉴定烤烟幼苗抗温度胁迫能力的有效指标,且以K326对温度胁迫最为敏感。

Effect of Temperature Stress on Growth and Physiological Indexes of Different Varieties of Flue-cured Tobacco Seedlings

Pot-culture tobacco with 5 true leaves was used as material. The experiment was carried out with three flue-cured tobacco varieties seedlings under the temperature stress to study the changes of chlorophyll contents, MDA contents, nitrate reductase contents, root vigor, stem length, maximum leaf length and the maximum leaf width. The results showed that: (1) The contents of chlorophyll and NRase reduced under temperature stress. (2) The MDA content in Yunyan 87 increased significantly under low temperature stress; The MDA content in Honghuadajinyuan under low temperature was not significantly different, but that under high temperature increased significantly; The MDA content in K326 variety under temperature stress was significantly higher than that in the control group. (3) The seedlings root vigor of Honghuadajinyuan and K326 under temperature stress was significantly higher than that of the control group. (4) The morphological index of K326 decreased significantly. (5) The cold resistance of Honghuadajinyuan was the strongest, Yunyan87 was the second and K326 was the weakest. (6) The high temperature resistance of Yunyan87 was the strongest, Honghuadajinyuan was the second, and K326 was the weakest.