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

wpc2bvpz快递10cpi ？x x x, Z x 6 x @ 8；HP DeskJet 500 HPDES500。PRS x @ 外汇@ x x,, 0 # | x 2 B V pz 快递10 cpi ?x x x, x 6 x @ 8；HP DeskJet 500 HPDES500。植物种间自然杂交的研究对于理解植物的进化具有重要的基础意义。这是因为估计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。本研究将探讨花粉管生长速率、种子败育以及昆虫和鸟类授粉方式对鸢尾（Iris fulva）、鸢尾（Iris hexagona）和鸢尾（Iris brevicaulis）自然杂交成功的影响。这些植物在人工条件下容易杂交，并且有许多由物种间杂交形成的自然杂交群体。因此，这个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更好地定义自然杂交是如何在许多植物物种中产生的。此外，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杂交农业上重要物种的尝试，从而限制杂交计划的效率。

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.