Controlled pollination in root and tuber crops is challenging. Complex ploidy, cross-incompatibility, erratic flowering patterns, outcrossing, etc., limit the efficiency of breeding progress in these crops. Half-sib breeding that involves random pollination among parents is a viable method to harness genetic gain in outcrossing crops that are problematic for performing planned and controlled pollination. The authenticity of resulting progenies from the half-sib breeding is essential to monitor the selection gain in the breeding program. Parentage analysis facilitated by molecular markers is among the available handy tools for crop breeders to maximize genetic gain in a breeding program. It can help to resolve the identity of half-sib progenies and reconstruct the pedigree in the outcrossing crops. This paper reviews the potential benefits of parentage analysis in breeding selected outcrossing root and tuber crops. It assesses how paternity analysis facilitates breeding activities and the ways it improves genetic gain in the root and tuber breeding programs. Conscious use of complementary techniques in the root and tuber breeding programs can increase the selection gain by reducing the long breeding cycle and cost, as well as reliable exploitation of the heritable variation in the desired direction.

Microsatellites or simple sequence repeats (SSR) are playing an important role in molecular breeding. This investigation was undertaken to study the genetic diversity among local sorghum accessions from two different agro-ecological zones of Burkina Faso and to assess the polymorphism within local improved varieties and a source (B35) exhibiting the stay-green trait. One hundred and eighty-six local and some exotic accessions were assessed using 26 SSR markers (including 14 markers linked to stay-green QTLs). DNA was extracted using Mixed Alkyl Trimethyl Ammonium Bromide method from dried sample after collection of leaves from three week old plantlets. The average number of alleles per locus was 4 with a medium value of gene diversity (He=0.45) across loci, indicating a low level of dissimilarity among local accessions. The genetic differentiation was significant between local and exotic materials and accessions were grouped according to their racial affiliation. The important finding was the presence of private alleles at markers linked to stay-green loci in the background of some local guinea accessions. The polymorphism between B35 and some local improved varieties for stay-green QTL indicates that most of the linked markers could be used in a breeding program through marker-assisted selection. Keywords: Sorghum, diversity, stay-green trait, marker, polymorphism.

Upland Rice Breeding in Uganda: Initiatives and Progress | InTechOpen, Published on: 2017-03-15. Authors: Jimmy Lamo, Pangirayi Tongoona, Moussa Sie, et