[关键词]
[摘要]
目的 明确不同干旱胁迫程度对金樱子幼苗叶片生理指标及生物量变化的影响,为金樱子大面积人工种植的干旱诊断和合理灌溉提供理论依据。方法 设置盆栽土壤含水量分别达到田间含水率的100%、90%、80%、70%、60%、50% 6个水平,测定不同干旱胁迫下金樱子叶片丙二醛(MDA)、脯氨酸(Pro)、光合色素含量及生物量指标。结果 随着干旱胁迫程度的增加,金樱子叶片MDA、Pro含量分别至重度干旱(W5,田间含水率60%)、严重干旱(W6,田间含水率50%)时才显著升高;光合色素含量除Car/(Chla+Chlb)比值外,均在轻中度干旱(W3,田间含水率80%)处理时达顶峰;株高在W6时才显著下降,地茎在W3时升至最大;根、茎、叶的鲜质量和干质量也是在W3时达到最大值。结论 金樱子对干旱胁迫的抗逆性较强,在轻中度干旱(W3,田间含水率的80%)时植株生长达到最佳状态,最有利于干物质积累及产量的形成。而田间含水率不宜低于60%,否则产生胁迫,同时生物产量也下降明显。
[Key word]
[Abstract]
Objective To determine the effects of different drought stress levels on the physiological indexes and biomass changes of the seedlings of Rosa laevigata, and to provide theoretical basis for the future drought diagnosis and rational irrigation of R. laevigata. Methods The content of malondialdehyde (MDA), proline (Pro), photosynthetic pigments and biomass indices in leaves of R. laevigata, under different drought stress were determined by setting up six soil water content levels of 100%, 90%, 80%, 70%, 60%, and 50% respectively. Results With the increase of the degree of drought stress, the content of malondialdehyde and proline in the leaves of R. laevigata was significantly increased only under serious drought (W5, 60% of the field water content) and severe drought (W6, 50% of the field water content). Except for the ratio of Car/(Chla + Chlb), photosynthetic pigment content peaked in light to moderate drought (W3, field moisture content 80%). Plant height was decreased significantly at W6, and the stem increased to its maximum at W3. The fresh and dry weights of roots, stems and leaves also reached their maximum at W3. Conclusion The resistance of R. laevigata to drought stress was strong, and the plant growth reached the best state under mild and moderate drought (W3, 80% of the field water capacity), which was most conducive to the formation of dry matter accumulation and yield. However, the field water holding capacity should not be less than 60%, otherwise stress will occur, and the biological yield will also decline significantly.
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[基金项目]
桂林市科技关项目(2016010305-1)