Enlarging Flower Display Vital for Cross-fertilized Alpine Herb

Primula tibetica is an inconspicuous herb distributed in the Himalayas where lacks pollinators.The species may undergo severe pollen limitation in the field,and makes an ideal model system for studying whether pollen limitation selects on the traits that increase the floral display in a case in which a small,inconspicuous plant undergoes

Differential Gene Expression Between Cross-Fertilized and Self-Fertilized Kernels During the Early Stages of Seed Development in Wheat

In order to understand molecular basis of cross-fertilized kernel advantage and heterosis, improved differential display of mRNA was used in this study to analyze alterations in gene expression between cross-fertilized and self-fertilized kernels at 2, 4, 6, 8, 10 and 12 days after pollination (DAP) by using 3 wheat hybrids with different level of heterosis. Four patterns of differential expression were observed: (i) bands observed in cross-fertilized kernels but not in self-fertilized kernels (BCnS); (ii) bands occurring in only self-fertilized kernels but not in cross-fertilized kernels (BSnC); (iii) cDNA over-expressed in cross-fertilized kernels compared to self-fertilized kernels (OEC); (iv) cDNA under-expressed in cross-fertilized kernels compared to self-fertilized kernels (UEC). Further analysis showed that BCnS is positively correlated with heterosis, but BSnC is negatively correlated with heterosis. Four differentially expressed cDNA fragments were verified by reverse-northern blot and sequence homology search in GenBank showed that one of them was new sequences; the other exhibited higher similarity to NBS-LRR type resistance protein, 1,6-bisphosphatase and photosystem Ⅱ chlorophyll a-binding protein psbB, respectively, which indicated diverse pathways may be involved in heterosis formation.

Impact of Bee Pollination on Yield of Faba Bean (<i>Vicia faba</i>L.) Grown under Semi-Arid Conditions

The effect of honeybee (Apis mellifera carnica) on yield was investigated in open-pollinated faba bean cultivars and three inbred generations produced from them (once-selfed, twice-selfed, and thrice-selfed). All entries were grown in cages under two pollination conditions: presence of bees (cross-pollination) or absence of bees (self-pollination). The open-pollinated generations gave the highest performance in the presence and absence of bees. In the presence of bees, the open-pollinated and their inbred entries gave higher performance in all of the studied traits than in the absence of bees;the average improvement in yield and its components was 22%. The highest improvement percentage in yield performance was shown by more inbred entries (thrice-selfed > once-selfed), indicating that in faba bean populations, the performance of inbred generations was chiefly associated with the tripping of flowers, which is usually governed by successfully fertilized flowers, i.e., plants result from selfing in faba bean population needs to be visited by pollinating insects (bees) to set more seeds. It concluded that honeybee has an important role in increasing faba bean yield in semi-arid conditions;hence, it is important to provide a pollinator friendly environment for their foraging places and nesting sites to secure food supply.