Variability in stomatal features and leaf venation pattern in India coffe (Coffea arabila L.) clutivars and their functional significance

Abstract

Abstract: Several stomatal characteristics viz. stomatal frequency, epidermal cell frequency, stomatal index, leaf area served per stoma, stomatal plastid number and stomatal guard cell length and leaf architecture including major and minor venation pattern was studied in ten Indian arabica Coffea arabica L.) cultivars. Significant variation was observed for all stomatal characteristics as well as the leaf venation pattern such as leaf size, areole size, number of vein endings entering the areole and vein islets termination number in different cultivars and is attributed to their origin involving different parents and selection pressure. The coefficient of variability calculated for all the stomatal features indicated that both stomatal guard cell length and stomatal plastid number were least variable whereas leaf area served per stoma was the most variable character among cultivars. Among all the stomatal features, high heritability (h 2) was observed for epidermal cell frequency. In all the cultivars, leaves were simple opposite with moderate mid-vein and entire margins. The major venation pattern was camptodromous type with festooned brochidodromous secondaries. Intersecondary veins were noticed in all cultivars. The marginal ultimate venation was either incomplete or incompletely looped. The functional significance of stomatal features and leaf vein architecture is discussed.