Performance In Agronomic Traits And Protein Content Of Progenies Obtained Through Unilateral Sexual Polyploidization In Potato

The genetic base of common tetraploid potatoe(sSolanum tuberosum L.) is narrow and new germplasm is urgently needed to be introgressed into the common potato. The purpose of this research is to introduce the desirable gene(s) present in diploid potatoes into common tetraploid potato, and broaden the genetic base of the common potato. Fourteen crosses were made using tetraploid potato cultivars (clones) as females and diploid potato hybrids (haploid Tuberosum-S. phureja hybrid or S. phureja-S. stenotomum hybrid) (2n pollen producer) as males via unilateral sexual polyploidization (4x-2x), and the first clonal generation of the tetraploid progenies produced were grown in Harbin and Jiagedaqi, respectively, in a Randomized Complete Block with 2 replicates. Two cultivars, Kexin 4 (early maturity) and Kexin 12 (high dry matter), were also included as controls. The performance of some traits of the tetraploid hybrids in the first clonal generation were assessed, including main stem number, plant height, plant vigor, tuber number/plant, tuber yield/plant, marketable tuber number/plant, marketable tuber yield/plant, crude protein content (based on both dry weight (DW) and fresh weight (FW)), dry matter, tuber shape, skin color, flesh color, and eye depth. Also, studied were correlations between seedling generation and first clonal generation for tuber number/plant and tuber yield/plant, and correlations between Harbin and Jiagedaqi for some important agronomic and quality traits. The results are as followings.1.Tuber number/plant and eye depth were improved in 4x-2x tetraploid hybrids compared with diploid potatoes; while protein content and dry matter content were enhanced in these tetraploid hybrids.2.Tuber number/plant, tuber yield/plant, marketable tuber number/plant, marketable tuber yield/plant, dry matter content in the 4x-2x tetraploid progenies were all higher in Jiagedaqi than in Harbin, while the reverse was true for protein content (DW).3.Selection for tuber number/plant and tuber yield/plant was ineffective in the seedling generation.4.Tuber yield/plant, marketable tuber yield/plant, and protein content (DW) were prone to be influenced by environments, and cross×location interactions were significant or highly significant, suggesting that selection for these traits in one location is not a good indicator for the other location. For tuber number/plant, marketable tuber number/plant, and dry matter content, the cross×location interaction was not significant, and therefore, the selection for these traits in one location can predict their performance in the other location.