Embryo Culture of New Hybrid of Pecan (Carya Illinoensis) with Walnut (J. Regia and J. Nigra)

Abstract

Present study was conducted to achieve intergeneric hybridization in Juglandaceae for the first time. Due to embryo abortion possibility, the embryo rescue technique was conducted via callus induction from immature hybrid embryo culture. For this reason, embryos were sampled at 20, 30, 40 and 60 days after pollination and cultured on two enrichment media (WPM and DKW). The developmental stage of immature embryo, kind of medium and addition of growth regulators to the induction medium played the role in promoting better callus and plantlet formation. The best quality and quantity of callus induction were achieved in 60 days’ explant. Maximum induction was in WPM and there was no callus induction in PGRs free medium. Browning was the most obstacle to conquer in callus proliferation. Germination of remained mature hybrid embryo until fruit harvest time was induced on three media (MS, WPM, and DKW). There were no significant differences between medium and male parents effect on germination parameters. But, MS and WPM performed better for hybrid embryo germination. The first germination was 7 days in MS and WPM and about 10 days for DKW after culture. In all medium the roots were robust and more developed than the leaves. The microplant transferred to soil after hardening.