Abstract

Water deficit is a major problem in banana grown under tropical and sub-tropical region climatic conditions. It affects plant growth and development and ultimately leads to a considerable bunch yield reduction or crop failure. Although the banana cultivars and hybrids are susceptible to water deficit, there is a marked genotypic variation in morphology of the plant and rooting pattern in banana in response to water deficit. The objective of this experiment was to investigate the possibility that the twelve banana cultivars and hybrids referred to as, Karpuravalli (ABB), Karpuravalli x PisangJajee, Saba (ABB), SannaChenkathali (AA), Poovan (AAB), Ney poovan (AB), Anaikomban (AA), Matti x Cultivar Rose, Matti (AA), Pisang Jajee x Matti, Matti x Anaikomban and Anaikomban x PisangJajee and coded as S₁, S₂, S₃, S₄, S₅, S₆, S₇, S₈, S₉, S₁₀, S₁₁ and S₁₂ might reveal cultivars specific diversity in the regulatory mechanisms underlying their different responses to water deficit with a view of establishing the most drought tolerant [Karpuravalli (ABB), Karpuravalli x PisangJajee, Saba (ABB)] banana cultivars and hybrids that can be grown under water deficit conditions in Tamil Nadu. The physiological and biochemical behavior in banana cultivars and hybrids subjected to water restriction were investigated during the 3rd, 5th, 7th and 9th month after planting (MAP). The parameters that were measured are the leaf relative water content, proline, total sugar, free amino acids and total soluble proteins. The experimental design carried out was at entirely split plot, with two water regimes considered as mail plot like stress (M1) and control (M2) and sub plot (S) taken as cultivars and hybrids. There was decrease in the leaf relative water content and soluble protein content in plants with decreased in water content. Results indicate that S₁ and S₂ has superior physiological traits under water deficit hence may be recommended for growing under water deficit conditions (50% available soil moisture) in tropical and subtropical regions.

Key words: Water deficit, banana, Relative water content (RWC), soluble protein, proline, free amino acid, total sugar.