The purpose of this study was to investigate the effects of various presowing treatments on the germinability(final germination percentage)and germination rate of loquat seeds in order to increase seedling production ...The purpose of this study was to investigate the effects of various presowing treatments on the germinability(final germination percentage)and germination rate of loquat seeds in order to increase seedling production in nurseries(applied research)as well as provide answers for important physiological issues related to loquat seeds and their seed coat(basic research).Three experiments were carried out with various pre-sowing treatments.These treatments included full or partial removal of seed coat(perisperm),partial cutting of cotyledons as well as moist chilling at 5℃ for 13 days and/or soaking the seeds in water or 250 ppm gibberellic acid(GA_(3))solution for 24 h.According to the results,cotyledons excision resulted in delayed germination,regardless of the presence or absence of the seed coat in comparison with the decoated seeds that demonstrated the highest germination rate amongst them.In addition,even the partial excision of seed coats affected positively both the germinability and the germination rate,compared to the control-intact seeds.Furthermore,control-intact seeds had a higher germination percentage when exposed to moist chilling independently of the application or not of gibberellin;while the combination of gibberellin application and moist chilling improved both the percentage and the rate of germination of decoated seeds.In conclusion,the role of perisperm(seed coat)in the germination procedure of loquat seeds seems to be important,indicating the existence of seed coat-imposed dormancy on loquat seeds.Finally,the existence of a mild endogenous embryo-dormancy on loquat is also discussed.展开更多
During the diversification of angiosperms, seeds have evolved structuralp chemical, molecular and physiolog- ically developing changes that specially affect the nucellus and endosperm. All through seed evolution, prog...During the diversification of angiosperms, seeds have evolved structuralp chemical, molecular and physiolog- ically developing changes that specially affect the nucellus and endosperm. All through seed evolution, programmed celldeath （PCD） has played a fundamental role. However, examples of PCD during seed development are limited. The present review examines PCD in integuments, nucellus, suspensor and endosperm in those representative examples of seeds studied to date.展开更多
文摘The purpose of this study was to investigate the effects of various presowing treatments on the germinability(final germination percentage)and germination rate of loquat seeds in order to increase seedling production in nurseries(applied research)as well as provide answers for important physiological issues related to loquat seeds and their seed coat(basic research).Three experiments were carried out with various pre-sowing treatments.These treatments included full or partial removal of seed coat(perisperm),partial cutting of cotyledons as well as moist chilling at 5℃ for 13 days and/or soaking the seeds in water or 250 ppm gibberellic acid(GA_(3))solution for 24 h.According to the results,cotyledons excision resulted in delayed germination,regardless of the presence or absence of the seed coat in comparison with the decoated seeds that demonstrated the highest germination rate amongst them.In addition,even the partial excision of seed coats affected positively both the germinability and the germination rate,compared to the control-intact seeds.Furthermore,control-intact seeds had a higher germination percentage when exposed to moist chilling independently of the application or not of gibberellin;while the combination of gibberellin application and moist chilling improved both the percentage and the rate of germination of decoated seeds.In conclusion,the role of perisperm(seed coat)in the germination procedure of loquat seeds seems to be important,indicating the existence of seed coat-imposed dormancy on loquat seeds.Finally,the existence of a mild endogenous embryo-dormancy on loquat is also discussed.
文摘During the diversification of angiosperms, seeds have evolved structuralp chemical, molecular and physiolog- ically developing changes that specially affect the nucellus and endosperm. All through seed evolution, programmed celldeath （PCD） has played a fundamental role. However, examples of PCD during seed development are limited. The present review examines PCD in integuments, nucellus, suspensor and endosperm in those representative examples of seeds studied to date.
