Study of morphological and anatomical traits of female flower and fruit development in pistachio (Pistacia vera)

Pistachio (Pistacia vera L.) with high cultivation in Iran has economic and nutrition importance. In this investigation, the morphological and anatomical traits of the female flower, development of endosperm and cotyledons were studied with cyto-histological techniques and light microscopy. In addition, fruit development was studied in different developmental stages. The results showed each of female flowers in panicle florescence has three-lobed stigma, a large pistil that attached to stigma with short style. One small bract is below 5 sepals in all flowers. Anatomical study reported the pistil have one carpel with single inverse ovule at its ovary. The endosperm is free nuclear firstly and then becomes cellular. Finally, this tissue replaces with cotyledons during embryo development. During the fruit development, the structure of the pericarp differentiated as exo-mesocarp and endocarp. Endocarp development continued until 95 days after full bloom (middle of May), and became hard and lignified in this time.The kernel show no abvious growth at this time but its growth increase after this time and completed in 145 DAF (last of July). Finally, fruit ripening continued and was cmpleted at 165 DAF (last of August) concurrent with harvesting time