Interspecific hybridizations between P. vulgaris and P. acutifolius
and between P. vulgaris and P. lunatus were investigated. Prefertilization
events were similar in inter- and intra-specific crosses. Fertilization
was completed in all crosses and the time of fertilization was
dependent on the maternal parent, reflecting differences in the time of
maturation...
Hybrids with abnormal development were obtained when particular
genotypes of Phaseolus vulgaris L. were crossed. The phenotypic
aberrations of the F₁s included retarded growth, chlorosis of the
trifoliate leaves and the formation of adventitious roots on the
hypocotyls. The expression of the abnormalities was dependent on the
temperature. At high...
Interspecific hybridization between Phaseolus vulgaris and P.
coccineus results in the formation of either mature F₁ seeds or abnormal
embryos, depending on the direction of the cross. However, normal as
well as abnormal embryos occur in the reciprocal F₂ populations. The
exact cause of abnormal embryo development is unknown. To...
Cytokinins are a group of plant hormones mediating cell division and
differentiation. Zeatin is a naturally occurring and highly active cytokinin that is rapidly
metabolized in Phaseolus seeds. The metabolites and enzymes mediating the conversion
have been studied extensively. Zeatin metabolic enzymes may be utilized in studying the
regulation of...
A critical balance of hormones is necessary for normal plant
development. Therefore, precise mechanisms must exist to maintain
proper levels of cytokinins, a group of hormones regulating cell
division and differentiation. Structural modifications of the naturally
occurring cytokinin, zeatin; including the oxidation, O-glycosylation
and reduction of the N⁶-side chain; may...
An enzyme catalyzing the formation of
O-glucosylzeatin in immature embryos of P. lunatus was
purified 2500 fold using ammonium sulfate precipitation
followed by affinity and anion exchange chromatography.
The enzyme uses trans-zeatin as substrate (Km 28 uM) but
not cis-zeatin. ribosylzeatin, or dihydrozeatin. Both
UDP-glucose and UDP-xylose can serve as...
Gene transfer via interspecific hybridization within Phaseolus has
been limited by abnormal hybrid development and the rapid loss of
hybridity in subsequent generations. The most advanced embryo
development occurs in P. vulgaris x P. coccineus where mature seeds
form. However, the reciprocal cross still results in abnormal embryos
unable to...