为了更快、更易选择甜菜品种,美国农业研究局遗传学家Doney D.L提出对甜菜生活力施加影响,其遗传差异性可以扩大。如果这一理论能成立,则过去10—15年的研究在未来的5—7年内可以实现。Doney把甜菜种在标准的温室条件生长一个月,然后剪去叶子,放于完全黑暗中,在没有光合作用的物质条件下,强迫它生长出新叶子。在这种条件下,甜菜植株必须依赖贮存的能量,那些光合最多而贮藏能量最多的甜菜植株——或者至少是利用它贮藏能量最好的植株——成活下来。其余的枯萎而死。Doney用线虫作另一试验, In order to make sugar beet varieties quicker and easier to choose, Doney D.L, a geneticist at the Bureau of Agricultural Research, has proposed that it exert an influence on the viability of sugar beet and that its genetic diversity can be extended. If this theory can be established, then the past 10-15 years of research in the next 5-7 years can be achieved. Doney grows the sugar beet seed in standard greenhouse conditions for a month, then shears the leaves and puts them in complete darkness, forcing them to grow new leaves in the absence of photosynthesis. Under these conditions, sugar beet plants must rely on stored energy, and sugar beet plants that have the most photosynthetic and most stored energy - or at least the ones that use them to store the best energy - survive. The rest wither and die. Doney used nematodes as another test,