籽粒苋根系生长与抗旱性的观察  

AN OBSERVATION OF THE ROOT SYSTEM GROWTH OF GRAIN AMARANTH AND ITS DROUGHT RESIST ANCE

作　　者：李家义[1] 王树安[1] 刘兴海 李绪厚 郭俊英 

机构地区：[1]北京农业大学

出　　处：《干旱地区农业研究》1989年第3期34-41,共8页Agricultural Research in the Arid Areas

摘　　要：通过对籽粒苋根系生长与抗旱性的观察表明:1,籽粒苋一生中,根系的生长呈“先快、后慢、更快、再慢”的变化趋势,这种变化趋势与不同时期籽粒苋自身的营养状况及根系当时所伸达土层的土壤紧实度有关。2,籽粒苋根系很长,成熟时主根的入土深度可达2.45米,而且侧根多、根系发达。单株一级侧根数可达约510条。庞大的根系特点,与其较强的抗旱性密切相关。3,从不同生育阶段根系与地上部的生长变化规律看:在3、4真叶期以前,籽粒苋以根系生长为主,地上部生长缓慢。以后随着生长期的推移,逐渐过渡到以地上部生长为主。4,籽粒苋抗旱性很强,当接近收获,土壤水分0～50cm降至10％以下时,整个田间生长基本正常,可获得较好产量,The growth of the root system of grain amaranth and its drought resistance were studied at different growing stages.The results were as follows:1. The rhythm of the growth of root system of grain amaranth is in a fast-slow,and then, faster-slower pattern.And the variation of the tempo of its growth seems to be related to the status of nutrition itself and the compactness of Soil in which the plant grows.2. The root system of grain amaranth is rather long. The maximum depth of its tap root at the maturing stage can reach 2.45m with numerous lateral roots. The maximum number of the primary lateral roots of an individual plant observed is 510,and the longest among them is about 86.5cm in length, It is supposed that the well-developed root system of grain amaranth might be closely related to its strong tolerance to drought and high adaptability to poor soil fertility.3. From the changing tempo of the top-root ratio, it could be that the value of the ratio is the largest during the first stage. i.e. it is the root system that grows slower, then the tempo of growth changes the other way round with the above-ground parts gradually taking the lead and the top-root ratio diminishing.4. Under the condition of lower soil moisture content (less than 10%)from 0—50cm depth during the ripening stage, the crop grew normally and gave a better output.

关 键 词：籽粒苋 根系 抗旱性 牧草 

分 类 号：S544.901[农业科学—作物学]