Shell Structure and Embryo Development of Pistacia vera L. and P. atlantica Desf. (Anacardiaceae) Following Intra- and Interspecific Pollination

Abstract

Fruits of Pistacia vera and Pistacia atlantica were sampled up to fruit maturity following intra- and interspecific pollination. Embryo and shell structure were investigated in relation to shell indehiscence and premature splitting of P. vera. The ponticulus of P. atlantica was formed from the funicle only, in contrast to that of P. vera, which developed from both the funicle and the ovary wall. This may be one of the causes of reduced interspecific as compared with intraspecific fertility. Shell indehiscence and premature splitting were more common following interspecific pollination of P. vera. Ovary wall and shell thickness at the suture were lower in P. atlantica than in P. vera, while the suture angle was greater. Following interspecific pollination of P. vera, both ovary wall and shell thickness at the suture were lower and the suture angle was greater than following intraspecific pollination. In the shells of some fruits, more than one groove was observed in areas other than the usual split zone. W...