Cytogenetical studies in the diploid interspecific hybrids of section Erectoides in the genus Arachis.

Abstract

Three diploid interspecific hybrids and two reciprocal hybrids were produced between the species of section Erectoides. The cytological analysis in two hybrids and their reciprocal crosses shows 10 bivalents at diakinesis and metaphase-I in most of the PMCs and 2-4 univalents are seen in about 10 to 15 percent of cells. Further the hybrid between A. sp. 9990×A. sp. 10002 reveals a ring of four chromosomes in approximately 18 percent of the PMCs. In the hybrid A. regonii×A. sp 9990 and its reciprocal, chromatin bridge is seen in 8.4 percent of the cells at anaphase-II, thus providing cytological evidences for the possible role of structural changes in speciation of the section Erectoides.