Relations Between Root System and Tuber Yield in the Hybrid Population of the Potato Plants

Abstract

268 unselected clones derived from crosses between cultivars and breeding materials were grown under field conditions and the relationship between the root system and tuber yield was investigated. The results obtained are summarized as follows: 1. In the pooled hybrid population, root dry weight (DW) and dry tuber yield (yield) ranged from 0.09 g/pl. to 5.68 g/pl. and from 106.1 g/pl. to 413.8 g/pl., respectively. Root DW had the highest correlation with stem DW (r=0.80***) and leaf DW (r = 0.68***). The morphological characters which related positively with these DW were root diameter, stem length and number of branches, whereas the number of roots correlated with the number of stems and tuber DW at the maximum stage of top DW. Clones with larger root DW, stem DW and leaf DW tended to have longer growing period and higher yields. 2. When the clones were classified into the six maturity groups, simple correlation coefficients of mean growing period to root DW and to yield were very high, 0.99*** and 0.97***, respectively. The positive relation of root DW to yield among the different maturity clones appeared to result from the connection of root DW to growing period. 3. The differences of yield among the clones of the same maturity seemed to be related to those of root DW and leaf DW in the earlier maturity groups. However, in the later maturity groups the ratios of tuber yield to root DW and to leaf DW might be important. © 1981, CROP SCIENCE SOCIETY OF JAPAN. All rights reserved.