Genotype Differences of Spatial Distribution between Potato (Solanum tuberosum L.) Root and Leaf and Their Effects on Potato Yield

To test the genotype differences of spatial distribution between potato(Solanum tuberosum L.)root and leaf and their effects on potato yield,genotype'Genyou No.1'and'Genyou No.4'with heavy dry root weight,drought and lodging resistance,and'Konafubuki'with high yield,super quality,light dry root weight,and lodging acceptance were used at the maximum stage of shoot growth(MSS)under rain-fed field.The results indicated:① The total root lengths within 0-120 cm depth and within 30-120 cm depth of'Genyou No.1'and'Genyou No.4'were significantly longer than 'Konafubuki';② The root systems of'Genyou No.1'and'Genyou No.4'were mostly distributed in the depth of 30-120 cm,while that of'Konafubuki'was mainly distributed in the layer of soil tillage(0-30cm);③ The leaf area distribution of'Genyou No.1'was even,while that of'Genyou No.4'was mainly concentrated in the middle and upper layer(40-80 cm),particularly in 60-80 cm(accounting for the total leaf area 41.7%).Therefore,the light absorption coefficient of'Genyou No.1'was significantly lower than those of'Genyou No.4'and'Konafubuki'.Thus,the increased tuber dry matter and tuber growth rate of'Genyou No.1'was the largest during the period from MSS to harvest;④ There were significant differences between genotypes in the plant height,main stem diameter and specific root length.The plant height and main stem diameter of'Genyou No.1'were the largest and its specific root length was the smallest,while the plant height and main stem diameter o'fKonafubuki'were the smallest,but its specific root length was the largest.