Drought-Induced Variation in Photosystem II Activity and Chlorophyll Index: Implications for Yield Performance in Mulberry Genotypes Article Swipe
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· 2025
· Open Access
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· DOI: https://doi.org/10.56557/ajocr/2025/v10i39655
· OA: W4413635074
The success of the sericulture industry depends critically on the production of high-quality mulberry leaves, is frequently constrained by moisture stress. The present experiment was carried out to assess the effect of moisture stress on four mulberry genotypes and three varieties in Rain Out Shelter at TNAU, Coimbatore. The period of work is from November, 2018 to April, 2019.120 days old mulberry plants were grown in pots and subjected to three water regimes viz., 100% PC, 50% PC and 25% PC for 30 days. Physiological traits such as chlorophyll fluorescence (Fv/Fm), chlorophyll index and chlorophyll stability index (CSI) were estimated before imposing stress and 30 days after drought stress. Higher chlorophyll fluorescence (Fv/Fm=0.78) and chlorophyll index (36.5) values were observed in mulberry genotype MI-0425 at severe drought stress. Genotype MI-0613 recorded lower fluorescence and chlorophyll index with higher reduction percentage of 41.67% and 51.77% respectively under stress conditions. CSI was altered by drought stress and decreased up to 55.35% and 60.05% in MI- 0613 and MI-0658 respectively. But lesser reduction was observed in genotypes MI-0425 (10.86%) followed by V1 (11.96%). V1 recorded higher yield under drought stress. While the genotype MI-0425 showed lesser reduction in yield and TDMA (Total Dry Matter Accumulation) under drought stress. It was clearly pronounced that mulberry with higher Fv/Fm values were found to have higher chlorophyll index resulted in lesser yield reduction at moderate and intense stress. Genotype MI-0425 and variety V1 performed well under moisture stress by maintaining higher fluorescence value coupled with higher CSI. Therefore, the study concluded that chlorophyll fluorescence, chlorophyll index, and CSI are effective indices for assessing drought tolerance in mulberry.
