Cyto-morphological and molecular characterization of Cajanus cajan × C. scarabaeoides F1 hybrid

Abstract

Cajanus scarabaeoides has many desirable agro- nomic traits that deserve attention for introgression into pigeonpea cultivars. An inter-specific F1 hybrid was raised using C. cajan (ICP-26) as seed parent and C. scara- baeoides (ICPW-94) as pollen parent. Hybridity of the F1 plant was affirmed by analyzing the morphological attrib- utes, such as seed coat color, leaf shape, brown striations in the petal, pod features, and intermediate branching type etc. Most of the pollen mother cells (PMC) in the F1 hybrid have shown regular meiosis, but in some PMCs chromosome heteromorphism was observed for two pairs of bivalents during diakinesis, leading to precocious separation of biva- lents (62.81 %) at metaphase-I, and bridge formation (7.44 %) and laggards (2.48 %) at anaphase-I. SDS-PAGE of two major seed protein fractions (albumin and globulin) detected five polypeptide bands (Mol wt. 40.7, 39.8, 32.4, 23.5 and 19.5 KDa) unique to C. scarabaeoides, the male parent, in the F1 hybrids that evidenced the hybridity of F1 plants. Further, RAPD and ISSR marker analysis revealed the hybrid nature of the putative F1 plant. These analyses showed the inheritance of 28 RAPD and 12 ISSR markers, unique to C. scarabaeoides - the pollen parent, to F1 hybrids. This complementary use of cyto-morphological analysis, and molecular marker based genotyping allowed precise evaluation of the C. cajan×C. scarabaeoides inter- specific hybrid.