柱花草是一类优良的热带豆科牧草，它主要以种子繁殖。超干贮藏是一项节能、简便、有效的种子贮藏技术。为了研究柱花草种子超干贮藏的效果及其对遗传的影响，该研究以贮藏10 a 的热研5号柱花草种子为材料，对种子超干、−20℃和常温（25～35℃）贮藏的效果进行比较，研究超干长期贮藏对种子发芽率、生活力、植物物候期、形态特征、农艺性状及遗传稳定性的影响。含水率为3.17%的超干种子贮藏10 a、含水率为8.70%的种子分别在−20℃和常温（25～35℃）贮藏10 a后，其发芽势分别为77.9%、71.3%、18.5%，活力指数分别为60.10、50.79、4.98；超干处理与−20℃贮存10 a的处理发芽势和活力指数之间的差异显著（P<0.05），与常温贮存10 a的处理之间的差异极显著（P<0.01），结果表明柱花草种子超干长期贮藏效果好。通过植物形态特征观察和扩增片段长度多态性（amplified fragment length polymorphism，AFLP）分子技术检测分析，柱花草种子超干贮藏不会引起种苗在植物形态表型变化和AFLP分子水平上的遗传变异。研究结果将为柱花草种子超干贮藏提供数据参考。%Stylosanthes spp. originated in central and South America, consisting of 44 species and subspecies, in a promising tropical legume forage. It is planted in one-third of the tropical and south subtropical area of the world in terms of variety. It mainly regenerates in the form of a seed, and it is planted and used in southern China. The seed is the conservation of germplasm, breeding, and material basis, and it is important material for physiological studies. This study goes into the development of the tropical pasture seed ultra-dry conservation, breeding, and germplasm resources for biodiversity conservation and utilization of great significance. The ultra-dried seed storage technique is energy efficient, effective, and easy to manipulate for seed storing. While most tropical crop seeds do not have dehydration tolerance, the ultra-dried storage technique is a constraint in these seeds. However, our previous study showed that the Stylosanthes guianensis seed has very high tolerance to ultra-dried storage. The ultra-dried seeds of S. guianensis with a moisture content of 3.17%has high tolerance to aging after treatment at 50℃for 15 days. These results show that ultra-dried treatment could increase the seeds storability of S. guianensis. The most suitable moisture content is 3%±0.2 for long-term ultra-dried storing. Ultra-dry treatment can improve storage stability. However, this does not mean that the lower the moisture content the better. Researches proved that when the moisture content lowered to a certain extent, the vitality of the seed dropped. Too much ultra-dry treatment does not have a positive effect on the seed longevity. In fact, it may even decrease it. The ultimate aim of seed storage is to preserve the innate hereditary feature and pass it without variation by harmful influences. When storing seeds, not only should the seeds’ high germinating ability be preserved, but genetic stability should also be kept. Therefore, the detection of the genetic stability of the storage seed was very important in evaluating the storage effects. Morphologic features, cytological markers, physiologic and biochemical indexes, and molecular researches could be applied in the study of the changes in genetic integrity. The purpose of this study was to dertmine the effects of ultra-dried seed storage for ten years through analyzing the seed germination, viability, phenology, morphological characteristics, agronomic traits, and genetic stability of Stylosanthes guianensis cv. Reyan No. 5 compared to the methods of -20℃ and room temperature storage. With three seed storing methods for 10 years, a seed with moisture of 3.17%at ultra-dry storing, a seed with moisture of 8.7% at -20℃ storing, and a seed with moisture of 8.7% at room temperature storing have a germination potential of 77.9%, 71.3%, and 18.5%, respectively and a vitality index of 60.10, 50.79, and 4.98, respectively. Both germination potential and vitality index have significant differences between an ultra-dry seed and a seed with moisture of 8.7%at-20℃storage for 10 years. There are very significant differences between a seed with moisture of 8.7%at room temperature storage and a seed in ultra-dry storage or a seed stored at-20℃for 10 years. The ultra-dry long-term storage for Stylosanthes seeds is the best method among them. An investigation on the Stylosanthes morphologic characteristics and its AFLP molecular analysis showed that the ultra-dry seed storage does not cause plant morphological phenotypes to change or AFLP molecular genetic variation. The ultra-dry storage seed of Stylosanthes can greatly reduce the energy in long term storing with characteristics of being simple, effective, and widely applicable. This result will be useful in the field of Stylosanthes germplasm conservation and breeding.
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