木薯新选048自交系采后生理腐烂（PPD）抗性评价及其生理变化分析

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Abstract：Postharvest physiological deterioration （PPD） poses a’significant constraint to the commercialization of cassava.In this study，we evaluated 166 germplasms from Xinxuan 048（XX048） inbred cassava line.The degree of tuber decay was assessed at 0，6，12，18，24 and 30 days postharvest，with corresponding physiological indicators measured.The results showed that X045，X126， X077， X088，and X147 browning occurred later. Notably the browning areas in the five germplasms remained below 10% （PPD Grade 1） by 30 day，indicating superior storage tolerance. In contrast， X024， X062，X085， X100，and X133 showed browning occurred earlier. After 24 days，the browning area in these germplasms exceded 50% ，and reaching 100% （PPD Grade 6）by 30day ，demonstrating their poor storage tolerance. These germplasms can serve as excellent resources for storage tolerance cassava breeding.Starch and dry matter contents are lower in storable germplasms，while β -carotene content is higher. MDA content and antioxidant enzyme（SOD，CAT，POD） activities increase significantly in the late storage phase，and greater increments in non-storable germplasms. Correlation analysis showed that the browning area was positively correlated with dry mater content，starch content and POD enzyme activity，while also showing positive associations with SOD and CAT enzyme activity as well as MDA content. Conversely，a negative correlation was observed with β -carotene content. These results suggest that cassava tubers with high dry mater content and starch content are more susceptible to postharvest decay and exhibit weak PPD resistance.This study provides valuable data for investigating the mechanisms underlying PPD resistance in cassava and supports the breeding of PPD-resistant varieties.The identified germplasms ofer a foundation for further research on storage tolerance，PPD resistance mechanisms，and cassava breeding program. These findings hold significant implications for cassva cultivation and postharvest management.

Key words： cassava;inbred line;storability; postharvest physiological deterioration（PPD）

木薯（ManihotesculentaCrantz）是大戟科木薯属植物，块根富含淀粉，与马铃薯、甘薯并称为三大薯类，是全球第六大粮食作物[1]。（剩余24959字）