营养胁迫对小麦幼苗生长和生理特性的影响

Impact of Nutrition Stress on the Growth and PhysiologicalCharacteristics of Wheat Seedlings

为了探究小麦幼苗生长潜力及其对营养胁迫的适应能力,通过沙培试验,设置了正常生长植株和种子营养物质缺失(仅去除胚乳、仅去除根系、胚乳和根系均去除)处理,考察了小麦苗期叶龄、生长速率、株高、根系、叶绿素含量(SPAD)、叶面积、干物质积累、生理特性的变化。结果显示,萌发36 h的小麦幼苗在营养缺失处理下均已具备独自存活能力。与未去除胚乳(正常植株和仅去除根系)的小麦幼苗相比,去除胚乳(仅去除胚乳以及胚乳和根系均去除)的小麦幼苗发育缓慢,需要更多时间才能达到与正常小麦相同的生长阶段,且在两叶一心时生长速率、株高、根长、SPAD、总叶面积和干重显著下降,长势明显较弱,可溶性蛋白、脯氨酸和丙二醛含量一直维持在较低的水平。与正常生长植株相比,仅去除根系的小麦幼苗能够快速适应营养胁迫,在两叶一心时生长速率、株高、根长和干重与正常植株基本一致,可溶性蛋白和脯氨酸含量显著增加,丙二醛含量显著降低。由此可见,苗期小麦种子营养物质缺失条件下幼苗生长迟缓,适应能力弱,影响小麦后期的生长和发育。

In order to explore the growth potential of wheat seedlings and their ability to adapt to nutrient stress,the treatments were set up for normal growth plants and seeds with nutrient deficiency,i.e.removing only endosperm,removing only root,removing both endosperm and root,with normal growth plants as control.The changes of leaf age,growth rate,plant height,root,chlorophyll content(SPAD),leaf area,dry matter accumulation and physiological characteristics of wheat at seedling stage were investigated.The results showed that wheat seedlings with 36 h of germination had independent survival ability under nutrient deficiency treatments.Compared with wheat seedlings without endosperm removed(normal growth plants and removing only root),wheat seedling with endosperm removed(removing only endosperm and removing both endosperm and root)developed slowly,took more time to reach the same growth stage as normal wheat,and the growth rate,plant height,root length,SPAD,total leaf area,and dry weight decreased significantly when two leaves unfolded.The contents of soluble protein,proline,and malondialdehyde content maintained at a low level.Compared with normal growth plants,wheat seedlings with only root removed were able to adapt to the nutrient stress quickly.The growth rate,plant height,root length,and dry weight were basically the same as that of normal growth plants;the contents of soluble protein and proline were significantly increased,and the content of malondialdehyde was significantly decreased when two leaves unfolded.It was found that the lack of nutrients in wheat seeds at seedling stage led to growth retardation and weak adaptability of wheat seedlings,which affected the growth and development of wheat at later stages.