PEG处理下小麦种子萌发期的性状变化与品种抗旱性级别划分

Changes of Traits at Seed Germination Stage and Classification of Drought Resistance of Wheat Varieties under Polyethylene Glycol( PEG) Treat Conditions

利用16.1%的PEG-6000高渗溶液为干旱胁迫剂,在人工摸拟土壤自然干旱环境下,研究了云南全生育期抗旱性不同的2种、5亚种70份小麦品种的种子发芽势、发芽率、初生根数目和长度、胚芽鞘和胚芽长度的变化,以及用这些形态性状鉴定云南小麦种子萌发期抗旱性和划分品种抗旱性等级的可行性。结果表明,与作对照的水培处理相比,在16.1%的PEG处理下,58.6%、17.1%、91.4%和41.4%的参试材料对应的发芽势、发芽率、胚根数和胚芽鞘长度出现了上升,80%和100%的参试材料的最大胚根长度和胚芽长度出现了显著或极显著下降;以发芽势、发芽率、胚根数、胚芽鞘长度的相对值和PEG处理下的根芽长度比为种子萌发期抗旱性鉴定的指标时,92.9%、94.3%、65.7%、72.9%和94.3%的参试材料对应的抗旱性是强和极强的,其中,有69.2%、72.7%、73.9%、68.6%和66.7%的材料的全生育期抗旱性是强和极强的;说明以这5性状作为小麦种子萌发期抗旱性鉴定的指标是可行的,但是,相对胚根数可能不适合用于圆锥小麦种子萌发期抗旱性的鉴定,而相对发芽势和相对发芽率则是鉴定小麦种子萌发期抗旱性最简便和有效的理想指标。

The changes of potentiality and germination percent of seeds,number and length of radicels,length of coleoptiles and embryos of70 wheat varieties with different drought resistances at whole growth period（ WGP） belonging to 5 sub-species（ ssp.） of 2 species in Yunnan province were studied,and the feasibility of identification and classification of drought resistance at seed germination stage on wheat varieties were analyzed using the traits. The result showed that when polyethylene glycol（ PEG） solution of 16. 1 % were as a droughty inducer and droughty conditions of natural soil,potentiality and germination of seeds,number of radicels and length of coleoptiles were enhanced of materials tested of 58. 6 %,17. 1 %,91. 4 % and 41. 4 %,correspondingly; and length of maximal radicels and embryos were remarkable or very remarkable reduced of varieties tested of 80 % and 100 %,correspondingly; When relative values of potentiality and germination percent of seeds,number of radicels and of length of coleoptiles,and ratios of radicels / embryos under PEG treat were as indexes of drought resistance identification at seed germination stage,the varieties that drought resistance were resistant and highly resistant（ R-HR） at seed germination stage（ SGS） were correspondingly 92. 9 %,94. 3 %,65. 7 %,72. 9 % and 94. 3 % of materials tested; the varieties that drought resistance were R-HR at WGP were correspondingly 69. 2 %,72. 7 %,73. 9 %,68. 6 % and 66. 7 % of R-HR-SGS varieties identified.The result illuminated that the 5 traits were available as indexes identifying drought resistance at seed germination stage of wheat,but relative number of radicels should not be fitted to identify drought resistance at seed germination stage of Triticum turgidum ssp.turgidum,and relative potentiality,germination percent of seeds should be the handiest and the most effective and the most perfect indexes.