Theme 12: Forage Breeding and Genetics
Description
This study was conducted to examine the potencial to increase the genetic variability of forage Arachis species, involving crosses between accessions of same species and crosses between different species, mostly of distinct taxonomic sections. Hybrids were produced between creeping, stoloniferous accessions belonging to section Caulorrhizae, Arachis pintoi x A. pintoi and A. pintoi x A. repens. Additional crosses involved section Caulorrhizae versus representatives of Erectoides (A. hermannii and A. paraguariensis) and Procumbentes (A. appressipila, A. kretschmeri, A. lignosa and A. vallsii). In intersectional crosses, the stoloniferous accessions were used as male parents. All hybrids were perennial and inherited the stoloniferous habit, being suitable for field propagation. Most intersectional hybrids failed to produce flowers, and in those that flowered, pollen stainability was low, from zero to 7 %, exceptionally 68 % in one plant. Arachis pintoi x A. repens hybrids were sterile, although showing pollen counts around 90 %. Yellow flowers were dominant over orange, cream and white, and appeared in all F1 crosses between parents with distinct flower colors. F2 plants were only obtained from intraspecific F1s. They segregate for flower color, always including the original parental colors and yellow. This work shows that new forage materials, with variable plant types, can be produced to enrich the forage Arachis germplasm, either by intraspecific hybridization of Arachis pintoi, or by interspecific hybridization, using stoloniferous male parents. Intraspecific hybrids produce segregating lines for breeding programs, while interspecific and intersectional F1s can be clonally propagated, incorporating genetic features of two additional sections.
Included in
Increase of Genetic Variability of Forage Arachis by Intra and Interspecific Hybridization
This study was conducted to examine the potencial to increase the genetic variability of forage Arachis species, involving crosses between accessions of same species and crosses between different species, mostly of distinct taxonomic sections. Hybrids were produced between creeping, stoloniferous accessions belonging to section Caulorrhizae, Arachis pintoi x A. pintoi and A. pintoi x A. repens. Additional crosses involved section Caulorrhizae versus representatives of Erectoides (A. hermannii and A. paraguariensis) and Procumbentes (A. appressipila, A. kretschmeri, A. lignosa and A. vallsii). In intersectional crosses, the stoloniferous accessions were used as male parents. All hybrids were perennial and inherited the stoloniferous habit, being suitable for field propagation. Most intersectional hybrids failed to produce flowers, and in those that flowered, pollen stainability was low, from zero to 7 %, exceptionally 68 % in one plant. Arachis pintoi x A. repens hybrids were sterile, although showing pollen counts around 90 %. Yellow flowers were dominant over orange, cream and white, and appeared in all F1 crosses between parents with distinct flower colors. F2 plants were only obtained from intraspecific F1s. They segregate for flower color, always including the original parental colors and yellow. This work shows that new forage materials, with variable plant types, can be produced to enrich the forage Arachis germplasm, either by intraspecific hybridization of Arachis pintoi, or by interspecific hybridization, using stoloniferous male parents. Intraspecific hybrids produce segregating lines for breeding programs, while interspecific and intersectional F1s can be clonally propagated, incorporating genetic features of two additional sections.
