准噶尔荒漠紫翅猪毛菜和散枝猪毛菜种子萌发特性的差异

通过对比研究不同变温和土壤含水量下,2个物种间萌发特性差异,吸水特性差异,以及两物种幼苗耐旱性,分析两物种紫翅猪毛菜(Salsola affinis C.A.Mey)、散枝猪毛菜(Salsola brachiata Pall.)种子萌发特性与物种分布特征的关系。结果表明:紫翅猪毛菜萌发率高于散枝猪毛菜。在(0/10)℃低温下,2种猪毛菜萌发率及发芽势最高,种子随着温度的升高,萌发率及发芽势均会下降。2个物种均有A、B、C、D类型种子,紫翅猪毛菜种子A→D萌发率逐渐下降,A、B型种子随着温度升高下降显著,而C、D型种子变化缓慢。散枝猪毛菜4种类型种子均在低温下有最高的萌发率,随着温度的升高,种子萌发率下降,且4种类型种子萌发率差异不明显。紫翅猪毛菜在2-3 h时吸水达到稳定,散枝猪毛吸水时间明显延长。紫翅猪毛菜随土壤含水量的降低,萌发率降低,且种子在同一水分梯度下,种子A→D萌发率逐渐降低。散枝猪毛菜种子在土壤含水量最大(26%)时,有最大的萌发率,在低水分10%时,B、C型种子的萌发率高于A型种子。2种猪毛菜幼苗都是随着干旱时间延长,耐旱性越弱,但紫翅猪毛菜幼苗耐旱性明显高于散枝猪毛菜。以上研究结果表明,紫翅猪毛菜和散枝猪毛菜种子萌发特性差异是决定二者在野外的分布区域上存在差异的重要原因。

Difference of Seed Germination Characteristics between Salsola affinis C.A.Mey and Salsola brachiata Pall.in Junggar Basin

To investigate the relationship between germination characteristic and species distribution,germination characteristic,water absorption characteristics,and seedling desiccation tolerance of Salsola affinis C.A.Mey and Salsola brachiata Pall under different temperature and soil water content were studied in this paper.The results showed that germination rates and germination potential decreased with the increasing of temperature,and both had the highest germination rate and germination potential at 0/10 ℃.But germination rate of S.afl~nis was higher than that of S.brachiata.Germination rates of four different S.affinis seeds types including A,B,C and D decreased with the order of them, among which it was seen a dramatically decrease in type A and B,but a slowly decrease in type C and D when temperature turned higher.Whereas,there was no significant difference in germination rates among four different S.brachiata seeds types. About 2-3 h later, seed water absorption in S.afl~nis entered stagnant stage,but it was longer in S.braechita.Germination rate of S.affinis decreased with the decreasing of soil moisture,and it decreased from type A to type D in the same water gradient.Germination rate of S.brachiata seeds was highest when soil moisture content was 26%.At 10%,germination rates of seed type B,C were higher than that of A type seeds.With the drought time prolonging,seedling desiccation tolerance in both species became weaker,but it was significantly higher in S.at~nis than in S.bracchita.The results indicated that seed germination characteristic in S.amnis and S.bracchita was an important factor in determining their distribution difference.