Chilling Tolerance of 10 Maize Genotypes as Related to Chilling‐induced Changes in ACC and MACC Contents

摘要

AbstractWe studied chilling‐induced changes of 1‐aminocydopropane‐1‐carboxylic acid (ACC) and of 1‐(malonylamino) cyclopropane‐1‐carboxylic acid (MACC) contents in seedlings of ten maize genotypes with different chilling tolerance. Seedlings at the third leaf stage were chilled at 5°C and at 65 RH. Immediately before and after two and five days of chilling the contents of ACC and of MACC in the third leaf were measured. Water content and – after recovery – the degree of necrotic injuries and the percentage of seedling survival were also determined.After 2 days of chilling, the ACC content increased in all genotypes investigated. The increase was significantly higher in the sensitive genotypes than in the tolerant ones. There was a significant correlation between ACC content and necrotic injuries of seedlings. Chilling for 5 days increased the ACC content further and the difference between the two groups of genotypes still existed.The MACC content increased after 5 days of chilling in all genotypes investigated. The increase was greater in the tolerant genotypes than in the sensitive ones. However, the difference in MACC accumulation between the two groups of genotypes investigated was not significant, and thus no correlation between MACC accumulation and chilling susceptibility was found.The possible causes for the increase of ACC and MACC contents under chilling conditions and the possibility of using the ACC content as an indicator of chilling tolerance in maize bree