In vitro embryo culture of interspecific hybrids between the kenyan lines of phaseolus vulgariis L. and phaseolus acutifolius A. gray

Abstract

The objective of this study was to examine the interspecific compatibility between the Kenyan Phaeseolus vulgaris L. lines (GLP 2, GLP 24, GLP X92 GLP 1004 and 1122) and Phae eo Lu e a cu t i f o l iu e Ao Gray lines (P. I. 310801, P.I.310606, P.I 263590, L-246-2, L-179, L-170, L-242-2, L-246-l2, L-242-6, CIAT G400l6, CIAT G40034, Buff Hood Arizona and White Hood Arizona) with the hope for future exchange of desirable genetic characteristics between the two species. Pre-mature abortion of hybrid embryos obtained from several crosses between the two species was successfully overcome by in vitro embryo culture. Rooting was poor among interspecific hybrids. N6_ benzyl adenine promoted shoot development but retarded rooting. Inclusion of both kinetin and indole-acetic acid in the basal medium did not significantly improve root development. However, root development was promoted by either excluding growth hormones from the basal medium or by using certain genotype combinations of various lines of Phaseolus vulgaris L. and Phaseolus acutifolius. xxiv Mature interspecific hybrids were produced between: 'GLP 24 and Buff Hood Arizona', GLP 1004 and CIAT G400161 , '1122 and P.L 310801'. The hybrids expressed various foliar morphological and growth characteristics which were overdo minant or intermediate between the parents. Two Fl hybrids (GLP 24 X Buff Hood Arizona) expressed leaf morphological characteristics e.g. acute leaf apices and indeterminate growth habit closely resembling 'Buff Hood Ar i z o na ", The Fl hybrid ('GLP 1004 X CIAT G400161 ) had acute leaf apices and indeterminate growth habit of ICIAT G400l61 , while other leaf characteristics eog. widths of the leaf lamina of terminal and lateral leaflets closely resembled 'GLP 10041 , The F1 hybrid (11122 X Pol. 3108011 ) had indeterminate growth habit of I Po 10 3108011 while leaf characteristics eogo rounded leaf bases of terminal leaflets closely resembled 6112260