The genetics and ecology of seed size variation in a biennial plant, Hydrophyllum appendiculatum (Hydrophyllaceae).

摘要: The goal of this study was to elucidate the sources seed size variation in Hydrophyllum appendiculatum, an outcrossing, biennial plant. genetic basis examined with a diallel breeding design. analysis did not reveal any evidence for additive variance, suggesting that could evolve response natural selection. A series greenhouse experiments conducted determine sensitivity weight number ecological variables. Seed affected by inbreeding depression: seeds produced self-pollinations were significantly lighter outcrossed seeds. Maternal plants differentially provision result crosses between subpopulations (separated 300 m) or populations 1.7 km). Mean independent pollen donors (one vs. many) sired on inflorescence; however, variance greater inflorescences pollinated multiple donors. Direct manipulations abiotic environment showed growing under full sunlight compared shaded plants. unaffected soil type, fertilizer addition, defoliation. Finally, I determined effect varying pollination intensity at level single inflorescence, and whole plant level. greatest had only 1 5 pollinated, least those 10 20 pollinated. At inflorescence level, weights where all flowers half Perhaps contributor species temporal decline within through flowering season. These results indicate maternal are capable producing uniform crops. Rather, final distribution population will necessarily vary be effects, heterogeneity environment, developmental constraints.