Heterosis and Variation of Yield Components in F₁ Hybrids Between Group Tuberosum and Group Andigena Potatoes¹

Abstract

Five clones of Solanum tuberosum L. Group Tuberosum (T) and five long‐day adapted clones of Group Andigena (A) were crossed to produce four populations (TT, AA, TA and AT) in such a way that there was selling in the intra‐Group crosses. The populations were grown for 2 years as spaced plants in a randomized, complete‐block design and compared for plant vigor, maturity, tuber number, mean tuber weight, and total yield to evaluate the potential of the inter‐Group hybrid (TA and AT) populations in broadening the genetic base of potato cultivar development. In four comparisons, the TA and AT populations outyielded the TT population by 8.6 to 32.9%. Also, the TA and AT populations generally had larger variance estimates for total yield. It is concluded from the analysis of population means for tuber number, mean tuber weight, and total yield that in the TA and AT populations the heterosis for total yield results largely from the multiplicative interaction of the two yield components. The TA and AT populations showed no consistent reciprocal differences. The TA and AT populations showed greater stability than the TT population. These results have important implications for potato breeding.