狗牙根诱变后代抗寒性评价

通过电解质外渗法和匍匐茎恢复试验对‘阳江’狗牙根及其12个通过形态鉴定选出的坪用价值高且花序密度低的诱变后代进行抗寒性鉴定。电解质外渗法结果表明:诱变后代间的抗寒性具有较大差异,其叶片半致死温度(LT₅₀)的变异范围为-7.6～-0.2℃(最低值与最大值相差7.4℃);参试材料抗寒性由强到弱依次为M18>M4>M26>M28> M22>阳江>M29>M31>M10>M37>M16>M1>M25,其中,有5个诱变后代抗寒性优于亲本,分别是M18、M4、M26、M28、M22。匍匐茎恢复实验结果表明:诱变后代M1、M22、M26、M31、M25在0℃和-5℃低温胁迫后的恢复生长率都高于亲本,恢复能力均优于亲本;M10、M37、M28在-5℃低温胁迫下,恢复生长能力低于亲本,抗寒性相对较弱,M16和M4在0℃和-5℃低温胁迫下,恢复生长率都低于亲本,抗寒性明显弱于亲本。综合2种方法鉴定结果显示:诱变后代M1、M25的恢复能力较强;M4、M28的叶片抗寒性较好,青绿期较长;M22、M18、M26的叶片抗寒性和匍匐茎恢复能力均较强;M29,M31的叶片抗寒性和匍匐茎恢复能力与亲本相似;M10、M16、M37的叶片抗寒性和匍匐茎恢复能力均较弱,整体抗寒性较弱。

Evaluation of Cold Tolerance of Mutant Offspring of Bermudagrass

According to morphological identification, 12 mutant progenies of ‘Yangjiang’ Bermudagrass with high turf value and low inflorescence density were selected to identify the cold tolerance by electrolyte leakage rate and stolon regrowth experiments. The electrolyte leakage rate showed that the variation range of LT₅₀ ranged from -7.6 ℃ to -0.2 ℃, and the difference between the minimum and maximum values was 7.4 ℃. It was obvious that the cold resistance of the mutant offspring varied greatly. The order of cold resistance from strong to weak was M18>M4>M26> M28 >M22>Yangjiang>M29>M31>M10>M37>M16>M1>M25. Five of the mutants had better cold resistance than the parents, namely M18, M4, M26, M28 and M22. The results of stolon recovery test showed that the mutant growth rates of M1, M22, M26, M31 and M25 were higher than those of the parents after low temperature stress at 0 ℃and -5 ℃, and the recovery ability was better than that of the parents. Under -5 ℃low temperature stress, the ability to restore growth of M10, M37 and M28 was lower than that of the parents, and the cold resistance was relatively weak. Under low temperature stress of 0 ℃ and -5 ℃, the growth rates of M16 and M4 were lower than that of the parents, and the cold resistance was significantly weaker than that of the parents.The results of the two methods showed that the mutants M1 and M25 had strong recovery ability. M4 and M28 had better cold resistance and longer green period. M22, M18 and M26 had stronger cold resistance and stolon recovery ability. The cold resistance of the leaves of M29, M31 and the recovery ability of the stolons were similar to those of the parents. The cold resistance and the recovery ability of the stems of M10, M16 and M37 were weak, and the overall cold resistance was weak.