土霉素对小麦毒性效应的品种间差异

Cultivar Differences in Toxic Effects of Oxytetracycline on Wheat (Triticum durum)

为了研究土霉素对小麦毒性效应的品种间差异,收集了63个小麦品种,根据土霉素对小麦种根影响的试验结果,从中筛选出对土霉素耐性相差最大的两个小麦品种,探讨了土霉素对这两个小麦品种叶片叶绿素含量的影响.结果表明:1)小麦对土霉素的耐性存在品种间差异,在供试的63个小麦品种中,核优1号对土霉素最敏感,而烟农21对土霉素最不敏感,二者的EC50值分别为1.25和54.21mg·L-1;2)土霉素处理能够显著降低小麦叶片叶绿素a、叶绿素b以及总叶绿素的含量,其中对土霉素敏感品种核优1号的抑制显著高于不敏感品种烟农21;3)就同一品种而言,土霉素胁迫条件下,叶片叶绿素a的降低程度明显高于叶绿素b,叶片叶绿素a/b的比值显著降低.土霉素对敏感品种核优1号叶绿素a/b比值的影响显著弱于不敏感品种烟农21.

Hydroponic experiments were performed to study the genotypic differences in toxic effects of oxytetracycline, a kind of tetracycline, on the root of wheat（Triticum durum）. Results were presented as follows： 1）The significant genotypic differences in responses of wheat to oxytetracycline were found. Among 63 wheat cultivars tested, cultivar Heyou 1 was the most sensitive to oxytetracycline with the EC50 value of 1.25mg·L-1, and cultivar Yannong 21 was most insensitive to oxytetracycline with the EC50 value of 54.21mg·L -1. 2）Contents of chlorophyll a, chlorophyll b and total chlorophyll in leaves of the two wheat cultivars tested decreased with the increase of oxytetracycline concentrations. The negative effects of oxytetracycline on the contents of chlorophyll a, chlorophyll b and total chlorophyll were more significant in the sensitive cultivar Heyou 1 than in the insensitive cultivar Yannong 21. 3）In the two wheat cultivars tested, oxytetracycline exhibited more inhibitory effects on chlorophyll a than on chlorophyll b. Oxytetracycline could also decrease the ratio of chlorophyll a to chlorophyll b and such effects of oxytetracycline on the sensitive cultivar were less than on the insensitive cultivar.