Physic nut (Jatropha curcas L) seed oil is a natural resource for the alternative production of fossil fuel. Seed oil production is mainly depended on seed yield, which was restricted by the low ratio of staminate flowers to pistillate flowers. Further, the mechanism of physic nut flower sex differentiation has not been fully understood yet. Quantitative Real Time-Polymerase Chain Reaction is a...

in 2007 and 2008, the influence of pollen source on the shell and kernel traits of resulting seeds and on fruit set was examined to evaluate the potential for xenia or metaxenia in persian walnut. pistillate flowers of ‘jamal’, ‘chandler’, ‘hartley’ and ‘pedro’ were crossed with the pollen of ‘serr’, ‘z60’ and ‘damavand’. the pistillate flowers on each female parent were covered about one week ...

BACKGROUND AND AIMS The distribution and differentiation times of flowers in monoecious wind-pollinated plants are fundamental for the understanding of their mating patterns and evolution. Two closely related South American Nothofagus species were compared with regard to the differentiation times and positions of staminate and pistillate flowers along their parent growth units (GUs) by quantita...

Evaluation of the pistillate flower abscission (PFA) potential of UC-67-13 and UC-67-11 was continued at two sites. At a high PFA site UC-67-13 PFA was only moderately lower than Serr for the third year. UC-67-11 demonstrated low PFA potential for a seconq year at this site. Higher PFA potential of UC-67-13 than UC-67 -11 was also found at a second site for a second year. No further evaluation ...

PFA was not different with shaded vs. exposed limbs of the same trees nor between shaded interior trees and outside ones with high light exposure. Tehama trees expressed lower PFA than adjacent Serre PFA of Tehama was also low at a site where Serr trees (removed 1982) had very high drop the previous three years. Fruitfulness of all monitored limbs in 1982 ranged from 6 to 97% and the earlier co...

Pistillate flower abortion (PFA) is the loss of nut-producing pistillate flowers early in the season, typically 2 to 3 weeks after bloom. PFA is the principal factor limiting productivity in ‘Serr’ walnut while affecting other cultivars to lesser and varying degrees. Research by Vito Polito at UC Davis showed that excessive pollen tubes growing down the style of the walnut pistillate flower pro...

The sequential separation of male and female function in flowers of dichogamous species allows for the evolution of differing morphologies that maximize fitness through seed siring and seed set. We examined staminate- and pistillate-phase flowers of protandrous Saponaria officinalis for dimorphism in floral traits and their effects on pollinator attraction and seed set. Pistillate-phase flowers...

The objective of this year's work was to confirm the role of pollen in pistillate flower abscission (PFA) of Serr walnut. Pistillate flower abscission was evaluated in individual trees along transects, beginning close to po11enizers and extending up to 640 feet away, in 12 orchards. It was also evaluated in controlled pollinations of bagged and unbagged Serr flowers with varying levels of Serr ...

The production of seed by both selfing and outcrossing, or mixed mating, may be selected for under conditions of variable pollinator availability. Seed production was examined following experimental manipulations of perfect and pistillate flowers of the gynomonoecious plant Silene noctiflora. Style excision experiments in a greenhouse demonstrated that autonomous selfing occurs in the perfect f...

BACKGROUND AND AIMS Monoecious plants have the capacity to allocate resources separately to male and female functions more easily than hermaphrodites. This can be advantageous against environmental stresses such as leaf herbivory. However, studies showing effects of herbivory on male and female functions and on the interaction with the plant's pollinators are limited, particularly in tropical p...