前言在加利福尼亚有限生长型加工番茄品种在座果后出现老叶坏死和变成青铜色的缺钾症状。这时,这些品种的叶柄中钾含量常以干重的6％左右减少到2％以下。半有限生长型鲜食品种在相似的条件下却很少出现这种缺钾症状,且此情况不能为施用钾肥所扭转。加工番茄品种缺钾的原因是由于相对小的根系不能迅速地吸收足够的钾以满足正在发育的果实的需要,鉴于吸收力弱或吸收率低的根系会限制果实生产率,因此对具有相应根系的番茄基因型进行了开发性研究。 Weaver和Bruner通过挖沟直接观察了番茄根系的外形,并测定了根的深度和侧向 Introduction In California, limited-growth tomato varieties suffer from old leaf necrosis and bronze-colored symptoms of potassium deficiency after fruit set. At this moment, the potassium content in the petioles of these varieties is often reduced to less than 2% by about 6% of dry weight. Half a limited-growth fresh varieties rarely show this potassium deficiency under similar conditions and this can not be reversed by the application of potash fertilizer. The reason for the potassium deficiency in processed tomato varieties is that since relatively small roots can not rapidly absorb enough potassium to meet the needs of developing fruit, given the weak or poorly absorbed roots that limit fruit productivity, Tomato genotypes were developed. Weaver and Bruner directly observed the shape of tomato root system by digging ditch and measured the depth and lateral direction