Effect of nitrogen and calcium stock plant nutrition on Petunia × hybrida leaf and anther explant growth in vitro

Abstract

Petunia × hybrida Hort. Vilm.-Andr. ‘Coral Sea’ stock plants were grown with a modified Hoagland's solution to determine the effect of stock plant N and Ca nutrition on subsequent leaf explant and anther growth in vitro. In separate experiments, N was 0, 75, 150 or applied at 0, 100, 200 or 400 mg 1 −1 as nitrate-N, and Ca was applied at 300 mg 1 −1. Leaf explants from plants grown with 100 mg 1 −1 N produced the greatest amount of callus, while those from plants grown with 200 and 400 mg 1 −1 N produced the highest number of shoots. Nitrogen treatments increased the anther fresh weight and the number of shoots per culture compared to anthers derived from stock plants that did not receive N. The fresh weight of shoots produced by leaf explants decreased with increasing Ca concentrations applied to stock plants. Anthers derived from stock plants treated with 0 mg 1 −1 Ca produced the highest number of shoots per culture. Anatomically, both filament and anther wall tissue produced callus, but no callus production from microspores was observed. Organs produced by anthers were diploid.