Improvement of Leaf Mustard F1 Hybrid by Using Cytoplasmic Male Sterility

Abstract

Transferring cytoplasmic male sterility of leaf mustard (Brassica juncea L.) which received from Wisconsin University, U.S.A., into 8 varieties of good leaf mustard by routine crossing. These good varieties were selected by Chiang Mai University. The F1 crosses were backcrossed with their male parents for four generations (BC₄). These BC₄ lines were crossed with good varieties of leaf mustard, 40R₂-3-4. The F1 hybrid varieties were tested in comparison with commercial varieties in winter 1998. Most F1 hybrid varieties did not form head. However, two F1 hybrid varieties, (4-4 x 19-H-12) x 40R₂ -3-4 and (4-4x 2R₂) x 40R₂ -3-4 formed 100% heading and yielded 34% and 13% higher than an average of commercial varieties, respectively. They also showed higher yield than 40R₂ -3-4 which is their parent, 25% and 5%, respectively.

            The study of methods for leaf mustard pollinations; hand pollination, bee pollination, and open pollination suggested that hand pollination was the best method for leaf mustard pollination. Making hand pollination the plant could produce 0.138 grams of pod weight and 1.0016 grams weight/1,000 seed. It also produced 8.5 seed/pod which was better than bee pollination and open pollination