Search

The integrated use of molecular marker-assisted selection (MAS) and anther culture has potential to significantly increase efficiency in plant breeding; however, reports on this kind of practical use are very limited. In the present study, we report the development of cytoplasmic male sterile (CMS) maintainers with aroma, disease resistance and red-brown hulls, as an example of integration of MAS and anther culture in rice breeding. A high-resolution melting (HRM)-based functional molecular marker was developed for the red-brown hull trait caused by a unique mutation (rbh1) in OsCAD2. Functional molecular markers for genes of rice blast resistance (Pi2), aroma (fgr) and red-brown hull (rbh1) were used for precise genotyping of individual plants in the BC1 and BC2F2 populations derived from a cross between CMS maintainers Huaxiang B (pi2–/rbh1–/fgr–) and Rong 3B (Pi2+/RBH1+/Fgr+). A total of 89 doubled haploid (DH) lines were generated from selected BC2F2 plants (Pi2+/rbh1–/fgr–) by anther culture. Seven DH lines were subsequently selected as the potential new CMS maintainers based on their overall performance and high resistance to blast. Our study demonstrated that integration of MAS and anther culture significantly accelerated the development of CMS maintainers with multiple stacked genes.

Plant growth rate is an essential phenotypic parameter for quantifying potential crop productivity. Under field conditions, manual measurement of plant growth rate is less accurate in most cases. Image-based high-throughput platforms offer great potential for rapid, non-destructive, and objective estimation of plant growth parameters. The aim of this study was to assess the potential for quantifying plant growth rate using UAV-based (unoccupied aerial vehicle) imagery collected multiple times throughout the growing season. In this study, six diverse lines of lentils were grown in three replicates of 1 m2 microplots with six biomass collection time-points throughout the growing season over five site-years. Aerial imagery was collected simultaneously with each manual measurement of the above-ground biomass time-point and was used to produce two-dimensional orthomosaics and three-dimensional point clouds. Non-linear logistic models were fit to multiple data collection points throughout the growing season. Overall, remotely detected vegetation area and crop volume were found to produce trends comparable to the accumulation of dry weight biomass throughout the growing season. The growth rate and G50 (days to 50% of maximum growth) parameters of the model effectively quantified lentil growth rate indicating significant potential for image-based tools to be used in plant breeding programs. Comparing image-based groundcover and vegetation volume estimates with manually measured above-ground biomass suggested strong correlations. Vegetation area measured from a UAV has utility in quantifying lentil biomass and is indicative of leaf area early in the growing season. For mid- to late-season biomass estimation, plot volume was determined to be a better estimator. Apart from traditional traits, the estimation and analysis of plant parameters not typically collected in traditional breeding programs are possible with image-based methods, and this can create new opportunities to improve breeding efficiency mainly by offering new phenotypes and affecting selection intensity.

The production of the first permanent, publicly available sunflower (Helianthus annuus L.) association mapping population (UGA-SAM1) provided material to test the usability of morphological descriptors for discriminating germplasm accessions. The objective of this study was to evaluate the phenotypic diversity in the UGA-SAM1 population and evaluate the usefulness of qualitative traits for the discrimination of genotypes. The SAM1 population consists of 285 accessions characterized for 20 morphological traits. The Shannon–Weaver diversity index (H′) was used to determine phenotypic diversity, whereas HOMALS (homogeneity analysis by alternating least squares) and association statistics were used to determine discriminative power of the descriptors. Phenotypic diversity was moderately high for the traits (0.74). The highest diversity was found in the less developed genotypes followed by non-oil genotypes. Pronounced associations in individual genotype groups and category traits, most notably for the maturity trait in the restorer line (RHA) oil group, resulted in both high association and diversity index values. The association test proved to be a useful addition to HOMALS analysis for determining the trait discriminative power. Adequate selection of traits used in germplasm evaluation can improve the efficiency of breeding programs, whereas the loss of variability could be lowered if diversity focused traits were used including leaf, seed, and certain flower traits, instead of only focusing on yield and quality. This is the peer-reviewed version of the following article: Terzić S., Zorić M., Seiler G. Qualitative traits in sunflower breeding: UGA-SAM1 phenotyping case study. Crop Science 2020, 60 (1), 303 – 319. [https://doi.org/10.1002/csc2.20059]

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.

Data were analyzed which included 13838 records belonged to 4100 Holstein cows over period 1988 to 2005, at the Nasr Dairy Cattle Station. The aim of the study is to evaluate sires genetically according to their daughters breeding efficiency which was estimated by Tomar equation and to estimate heritability and phenotypic trend for breeding efficiency. General Linear Model within SAS program was used to investigate the effect of some fixed factors on the breeding efficiency. The overall breeding efficiency ratio was 79.91% .Component of variance for random effects was estimated by MIVQUE method. Firas Al-Samarai