Abstract:

To study the characteristics of stem growth and sugar accumulation in sweet sorghum under soil salt stress in the later stage of growth， Liaotian 1 sweet Sorghum variety was used as the material， with 5 soil salt contents at 1.02， 2.15， 2.50， 3.00 and 4.59 g·kg^-1. The growth indicators and sugar content of stem during flag leaf stage， filling stage， dough stage and ripening stage were measured under different salt stresses， and comprehensive analysis and evaluation were conducted using analysis of variance and membership function method. The results showed that under the same soil salt stress， with the growth period progresses， the height and stem diameter of Liaotian 1 remained stable after the filling stage，the fresh weight and dry weight showed a trend of first increasing and then decreasing，brix， total sugar， and sucrose gradually accumulate，the contents of fructose and glucose showed a trend of first decreasing and then increasing. During the same growth stage， with the increase of soil salt content， the height， stem diameter， fresh weight， dry weight， brix， total sugar content and sucrose content of sweet Sorghum showed a trend of first increasing and then decreasing，the content of glucose and fructose continues to decrease；the plant height， stem diameter， fresh weight， dry weight， brix， and total sugar all reached their maximum values under a salt treatment of 2.15 g·kg^-1 . The sucrose content reached to maximum value under the salt treatment of 2.50 g·kg^-1 . When the soil salt content exceeded 3.00 g·kg^-1， the stem growth indicators and sugar content significantly decreased. Therefore， an appropriate soil salt content （2.15 g·kg^-1） could promote the growth and sugar accumulation in Liaotian 1. However， when the soil salt content exceeds 3.00 g·kg^-1， the growth and sugar accumulation of stems were inhibited， and the higher the soil salt content， the more significant the inhibitory effect. Above results provided a basis for the study of the stress resistance mechanism of sweet Sorghum and the development of cultivation techniques for planting sweet Sorghum on marginal lands such as saline alkali land.

Key words: soil salt stress, sweet Sorghum, late growth stage, sugar content in stem

摘要：

为研究土壤盐分胁迫下甜高粱生育后期茎秆生长及其糖分积累的特征，以辽甜1号甜高粱品种为材料，设置1.02、2.15、2.50、3.00和4.59 g·kg^-1共5个土壤盐分含量，测定不同盐分胁迫下，挑旗期、灌浆期、蜡熟期和完熟期甜高粱茎秆生长指标及糖分含量，并采用方差分析和隶属函数法进行综合分析评价。结果表明，相同土壤盐分胁迫下，随着生育期进展，辽甜1号的株高和茎粗在灌浆期后保持稳定，鲜重和干重呈先上升后下降的变化趋势，锤度、总糖及蔗糖逐渐积累，而果糖和葡萄糖含量呈先下降后上升趋势。同一生育时期，随着土壤盐分含量的增加，甜高粱株高、茎粗、鲜重、干重、锤度、总糖含量和蔗糖含量呈先上升后下降趋势，葡萄糖和果糖含量则持续降低；株高、茎粗、鲜重、干重、锤度、总糖均在2.15 g·kg^-1的盐分处理下达到最大值；蔗糖含量在2.50 g·kg^-1盐分处理下达到最大。当土壤盐分含量超过3.00 g·kg^-1时，茎秆生长指标及其糖分含量明显下降。因此，适宜的土壤盐分含量（2.15 g·kg^-1）可以促进辽甜1号的茎秆生长和糖分积累，但当土壤盐分含量超过3.00 g·kg^-1时，茎秆的生长和糖分积累受到抑制，且土壤盐分含量越高，抑制作用越显著。研究结果为甜高粱的抗逆机理研究和利用盐碱地等边际性土地种植甜高粱的栽培技术研发提供依据。

关键词: 土壤盐分胁迫, 甜高粱, 生育后期, 茎秆糖分