Stomate Density and its Relationship to Water‐Use Efficiency of Blue Panicgrass (<i>Panicum antidotale</i> Retz.)¹

Abstract

Six clones of blue panicgrass ( Panicum antidotale Retz.) representing three diverse sources of germ plasm were used to evaluate the association between stomate density and water‐use efficiency. Silicone rubber impressions were taken on the abaxial and adaxial leaf surfaces of four plants from each clone. Leaves were selected from the top, middle, and base of the culm and impressions were taken at the base, middle, and tip of each leaf. Stomate density of blue panicgrass clones ranged from 78 to 165 per mm2. Leaves adjacent to the inflorescence had significantly lower stomate density than those at the middle and base of the culm. No difference was found among stomate densities at the three positions on a leaf. A nonsignificant association was obtained when wateruse efficiency and stomate density were correlated for the six clones. Drouth tolerant clones had fewer stomates per unit area than drouth susceptible clones.