Screening and Characterization of Mulberry (Morus spp.) Genotypes for Enhanced Photosynthetic Efficiency and Higher Leaf Yield to Enhance Silkworm Growth and Productivity

Sericulture is an agro-based industry where mulberry supports silkworm growth and silk production. Mulberry is also economically and ecologically important beyond sericulture. The present study was undertaken to evaluate the physiological basis of yield variation among 23 mulberry genotypes/varieties with an emphasis on identifying stable and high-performing varieties suitable for diverse agro-climatic conditions. The genetic and physiological variability in photosynthesis and associated traits such as leaf area, LAI, chlorophyll fluorescence and chlorophyll index were studied in promising mulberry genotypes, at 45 and 60 days after pruning (DAP). Based on gas exchange parameters, ten superior genotypes were selected and further assessed for key physiological traits, like chlorophyll pigment composition, carotenoid content, and plant water relation traits (MC,MRC,and pWUE). Significant variation was observed among genotypes for all the parameters studied. Variety V1 consistently exhibited superior performance, recording higher photosynthetic rate, stomatal conductance, chlorophyll content, carotenoids, moisture retention capacity (MRC), and water use efficiency (WUE), followed by G4 and Morus indica. These traits were positively correlated with enhanced photosynthetic efficiency, improved water relations, and better stress tolerance. Consequently, V1 recorded the highest leaf yield per plant, followed by G4, while lower-performing genotypes such as S-54 and Kanva-2 exhibited reduced physiological efficiency and yield. The study highlights the strong interrelationship among physiological traits and their collective influence on leaf yield, suggesting that these parameters can serve as reliable selection criteria for identifying high-yielding and superior mulberry genotypes for successful sericulture activity.