Reproductive Biology and Natural Selection and the Formation and Maintenance of Louisiana Iris Hybrid Populations

WPC 2 B V P Z 10cpi ? x x x， Z X 6 X @ 8 ; X @ HP DeskJet 500 HPDES500.PRS X @ x X，，0 FX @ #|X 2 B V P Z 10cpi ? x x x， X 6 X @ 8 ; X @ HP DeskJet 500 HPDES500.PRS X @ x X，，0 FX@9317654 Arnold 植物物种间自然杂交的研究对于理解植物的进化具有根本的重要性。 这是因为估计有70%的植物物种是通过其他物种之间的自然杂交而产生的。 此外，人类使用的几乎所有粮食和纤维作物都反映了自然或人工杂交的结果，从而提高了生产力和营养价值。 这项建议中概述的研究将检查花粉管生长速度、种子败育以及昆虫和鸟类授粉模式对植物物种之间自然杂交成功的影响 虹膜 fulva , 虹膜 六角形 得双曲正弦值. 虹膜 短茎 . 这些植物在人工条件下很容易杂交，并且通过物种之间的杂交形成了许多自然杂交种群。 因此，这种物种复合体将允许确定哪些过程在限制和促进自然和实验杂交中是重要的。 这样的理解应该允许一个更好的定义如何自然杂交已经发生在许多植物物种。 此外，来自这些研究的数据将非常适用于植物育种者，他们需要知道什么机制可能会限制他们尝试杂交农业上重要的物种，从而限制杂交程序的效率。

WPC 2 B V P Z Courier 10cpi ? x x x , Z x 6 X @ 8 ; X @ HP DeskJet 500 HPDES500.PRS x @ x X , , 0 FX @ #| x 2 B V P Z Courier 10cpi ? x x x , x 6 X @ 8 ; X @ HP DeskJet 500 HPDES500.PRS x @ x X , , 0 FX @ 9317654 Arnold The study of natural hybridization between plant species is of fundamental importance for understanding the evolution of plants. This is due to the fact that an estimated 70% of all plant species have arisen through natural crosses between other species. Furthermore, almost all food and fiber crops used by humans reflect the result of natural or manmade crosses resulting in improved productivity and nutritive value. The studies outlined in this proposal will examine the effect of pollen tube growth rate, seed abortion and patterns of insect and bird pollinations on the success of natural crosses between the plant species Iris fulva , Iris hexagona , and Iris brevicaulis . These plants hybridize readily under artificial conditions and there are numerous natural hybrid populations formed by crosses between the species. Therefore, this species complex will allow a determination of what processes are important in limiting and promoting natural and experimental hybridization. Such an understanding should allow a better definition of how natural hybridization has come about in numerous plant species. In addition, data from these studies will be very applicable to plant breeders who need to know what mechanisms might restrict their attempts to cross agriculturally important species and thus limit the efficiency of crossing programs.