Growth acceleration of plants by UV-C rays irradiation for he comming global warming

在移栽前，用相同强度(23MUW)的UV-C辐射蔬菜幼苗，照射时间从0到150分钟不等。从植物生长的Logistic理论出发，从植物生长的最优因素--环境因素的作用形式之一--UV-C射线的作用形式之一--UV-C辐射对植物生长的促进和抑制两方面进行了研究。这意味着存在一个最有利于植物生长的照射时间值，它对植物生长的促进作用比正常情况要大得多。UV-C辐射后2周出现上述结果，作为促进生长的关键点，在照射后1周左右，各处理对叶片的生长均有抑制作用，同时根系活力增强。通过水培试验证实了这一点，即在相同的叶片抑制时间内，可溶性氧的消耗速率增加很大。通过测定光合作用速率、蒸腾速率和气孔导度，与未处理的蔬菜相比，UV-C辐射使水分利用效率(=光合作用/蒸腾速率)在第一周由低到高的变化很大。通过夏季和冬季气温对辐照幼苗生长影响的实验表明，高温下的抑制持续时间比低温下的短。夏季田间加速生长的程度较高，这意味着利用UV-C射线育苗的方法可能是应对全球变暖的有利方法之一。

We irradiated UV-C rays on plant seedlings of vegetable under same intensity (23 muW), changing duration from 0 to 150 minutes, just before transplant. Plants grew much more at about 30 minutes of irradiation, and less under longer irradiation, that is, plant growth were effected in both ways of acceleration and inhibition depending on duration of irradiation of UV-C rays.We considered this phenomena from point of view of the logistic theory for plant growth, and made clear the mechanism the optimum factor, one of the action form of environment elements. This means that there is the most favorable value of irradiation time for plant growth, which accelerate growth much more than the normal. Such result was appeared in two weeks after UV-C rays irradiation.As the key point of acceleration of growth, there was the inhibition of growth to leaves in every treatments during about one week after irradiation, and activity in roots was increased in the same time. We confirmed it by the hydroponic cultivation, that is, the comsumption rate of disolved oxygen increased quite large in the same duration of inhibition of leaves.Though measurements of photosynthetic rate, transpiration rate and stomata conductance, water use efficiency (= photosynthetic rate/transpiration rate) were changed greatly by UV-C rays irradiation from low in the first one week to high in the next 2-3 weeks, comparing to the non-treated vegetable.By the experiments on the effect of air temperature on growth of irradiated seedlings in summer and wingter, it was made clear that the duration of inhibition was shorter in high temperature than in lower temperature, and the degree accelerated growth in the field was higher in summer, This means that such method using UV-C rays to plant seedlings may be one of favorable methods for taking measurement against comming global warming.