U.S.-New Zealand Cooperative Research: Breeding Improved Pasture Legumes from the Cross Trifolium ambiguum x T. repens

该奖项将使肯塔基大学的伊丽莎白·G·威廉姆斯博士与新西兰帕默斯顿北部科学与工业研究部草原分部的沃伦·M·威廉姆斯博士和约翰·范登·博施博士开展合作研究。这些研究人员将创造白三叶和库拉三叶草的种间遗传杂交，以构建高世代杂交和与双亲回交的育种群体。白三叶，白三叶，是美国和新西兰的主要牧草。虽然这种三叶草在水分充足的情况下能够经受住重度放牧，从而在可消化能量和蛋白质以及共生固氮方面改善了草原的质量，但不幸的是，它的使用受到了在较低水分条件下缺乏持久性的限制。库拉(高加索)三叶草，具有强大的地下多年生根和根茎系统，既具有较强的抗旱性，又对影响白三叶的多种病毒表现出抗性。肯塔基大学的工作人员将把他们的工作重点放在通过种子胚胎挽救技术来产生新的杂交后代上，这项技术是他们与染色体加倍和杂交材料的组织培养一起开发的。病毒测试研究也将在美国进行。新西兰调查人员将把工作重点放在X射线照射以加强遗传交流、进一步开发高级世代杂交品种以及对新杂交材料的肥力和农艺性能进行选择上。美国和新西兰的研究人员在北半球和南半球开展合作，使试验性杂交三叶草作物的种植每年翻了一番。

This award will enable collaborative research between Dr. Elizabeth G. Williams of the University of Kentucky and Dr. Warren M. Williams and John Vanden Bosch of the Grasslands Division, Department of Scientific and Industrial Research located at Palmerston North, New Zealand. These researchers will produce interspecific genetic hybrids between white clover and kura clover in order to construct breeding populations of advanced generation hybrids and backcrosses to both parents. White clover, Trifolium repens, is a major pasture legume in both the U.S. and New Zealand. While this clover has the ability to withstand heavy grazing if moisture is adequate, thus improving the quality of grasslands both with respect to digestible energy and protein, and in terms of symbiotic nitrogen fixation, unfortunately its use is limited by a lack of persistence under lowered moisture conditions. Kura (Caucasian) clover, Trifolium ambiguum, possessess a vigorous underground perennial root and rhizome system and is both more drought resistant and shows resistance to a number of different viruses which affect white clover. The University of Kentucky staff will focus their activity on the generation of new hybrids through a seed embryo rescue technique which they have developed along with chromosome doubling and tissue culturing of hybrid materials. Virus testing studies will also be conducted in the U.S. The New Zealand investigators will focus their work on X-irradiation to enhance genetic exchange, the development of further advanced generation hybrids, and the selection for fertility and agronomic performance of the new hybrid materials. The collaboration between the U.S. and New Zealand investigators, working in the Northern and Southern Hemispheres, enables a doubling in the growing of experimental hybrid clover crops each year.