Combining Genetic Gain and Diversity in Plant Breeding: Heritability of Root Selection in Wheat Populations

To increase the resilience of agroecological farming systems against weeds, pests, and pathogens, evolutionary breeding of diversified crop populations is highly promising. A fundamental challenge in population breeding is to combine effective selection and breeding progress while maintaining intraspecific diversity. A hydroponic system was tested for its suitability to non-destructively select root traits on a population level in order to achieve genetic gain and maintain diversity. Forty wheat progenies were selected for long seminal root length (SRL) and 40 for short SRL from a wheat composite cross population grown in a hydroponic system. Wheat progenies were multiplied, and a subset evaluated again in a hydroponic system. Preliminary tests in soil and competition experiments with a model weed were performed. The hydroponic selection for long SRL led to an increase of SRL by 1.6 cm (11.6%) in a single generation. Heritability for selection of SRL was 0.59. Selecting for short SRL had no effect. The preliminary soil-based test confirmed increased shoot length but not increased SRL. Preliminary competition experiments point to slightly improved competitive response of wheat progenies but no improved competitive effect on mustard. These results indicate a heritable selection effect for SRL on a population level, combining genetic gain and intraspecific diversity.

Development of Sorghum Genotypes for Improved Yield and Resistance to Grain Mold Using Population Breeding Approach

The infection caused by grain mold in rainy season grown sorghum deteriorates the physical and chemical quality of the grain, which causes a reduction in grain size, blackening, and making them unfit for human consumption. Therefore, the breeding for grain mold resistance has become a necessity. Pedigree breeding has been widely used across the globe to tackle the problem of grain mold. In the present study, a population breeding approach was employed to develop genotypes resistant to grain mold. The complex genotype × environment interactions (GEIs) make the task of identifying stable grain mold-resistant lines with good grain yield (GY) challenging. In this study, the performance of the 33 population breeding derivatives selected from the four-location evaluation of 150 genotypes in 2017 was in turn evaluated over four locations during the rainy season of 2018. The Genotype plus genotype-by-environment interaction (GGE) biplot analysis was used to analyze a significant GEI observed for GY, grain mold resistance, and all other associated traits. For GY, the location explained a higher proportion of variation (51.7%) while genotype (G) × location (L) contributed to 21.9% and the genotype contributed to 11.2% of the total variation. For grain mold resistance, G × L contributed to a higher proportion of variation (30.7%). A graphical biplot approach helped in identifying promising genotypes for GY and grain mold resistance. Among the test locations, Dharwad was an ideal location for both GY and grain mold resistance. The test locations were partitioned into three clusters for GY and two clusters for grain mold resistance through a “which-won-where” study. Best genotypes in each of these clusters were selected. The breeding for a specific cluster is suggested. Genotype-by-trait biplots indicated that GY is influenced by flowering time, 100-grain weight (HGW), and plant height (PH), whereas grain mold resistance is influenced by glume coverage and PH. Because GY and grain mold score were independent of each other, there is a scope to improve both yield and resistance together.

Breed Ancestry, Divergence, Admixture, and Selection Patterns of the Simbra Crossbreed

In this study, we evaluated an admixed South African Simbra crossbred population, as well as the Brahman (Indicine) and Simmental (Taurine) ancestor populations to understand their genetic architecture and detect genomic regions showing signatures of selection. Animals were genotyped using the Illumina BovineLD v2 BeadChip (7K). Genomic structure analysis confirmed that the South African Simbra cattle have an admixed genome, composed of 5/8 Taurine and 3/8 Indicine, ensuring that the Simbra genome maintains favorable traits from both breeds. Genomic regions that have been targeted by selection were detected using the linkage disequilibrium-based methods iHS and Rsb. These analyses identified 10 candidate regions that are potentially under strong positive selection, containing genes implicated in cattle health and production (e.g., TRIM63, KCNA10, NCAM1, SMIM5, MIER3, and SLC24A4). These adaptive alleles likely contribute to the biological and cellular functions determining phenotype in the Simbra hybrid cattle breed. Our data suggested that these alleles were introgressed from the breed's original indicine and taurine ancestors. The Simbra breed thus possesses derived parental alleles that combine the superior traits of the founder Brahman and Simmental breeds. These regions and genes might represent good targets for ad-hoc physiological studies, selection of breeding material and eventually even gene editing, for improved traits in modern cattle breeds. This study represents an important step toward developing and improving strategies for selection and population breeding to ultimately contribute meaningfully to the beef production industry.

The Critically Endangered White-rumped Vulture Gyps bengalensis in Sigur Plateau, Western Ghats, India: Population, breeding ecology, and threats

The present study aimed to assess the population status, breeding ecology, and conservation threats of Critically Endangered White-rumped Vulture in Sigur Plateau, Tamil Nadu, India from June 2011 to May 2012. The population of White-rumped vulture was estimated in the roosting and nesting sites twice in a month. Nesting colonies were systematically visited four times in a month during the breeding season to study nesting and breeding ecology. Carcasses and vulture counting was done by opportunistic count method. Two sets of questionnaires namely ‘precise and closed’ and ‘broad and open-ended’ were developed to asses the people’s perception on vulture conservation. The overall population of White-rumped Vultures was estimated about 70 to 115 individuals. In total, 68 nests were observed in two nesting colonies. Most of the nests (97%) were recorded on Terminalia arjuna and only 3% on Spondias mangifera. Among the 68 constructed nests, 34 were incubated and 30 chicks were fledged out from the nests with 88% breeding success. Feeding behavior was observed from 28 carcasses, Vultures were attended only 15 caracasses an average of 56.04±3.29 individuals of vultures were recorded. Interestingly, Elephant (61.8±5.1) and Indian Gaur (58.5±0.3) carcasses were attracted in greater numbers of vultures in susiquent days (3.5±0.2) than other carcasses. People’s attitude to vulture conservation was positive and useful in 90.82% of the cases (n=99). Cattle carcass disposal method favored to vultures in these regions. The Sigur Plateau to be declared as “Vulture Sanctuary” in order to legally protect and conserve the country’s southern-most wild and viable Critically Endangered White-rumped Vulture population in the landscape.

DNA barcoding of Oryza: conventional, specific, and super barcodes

Key message We applied the phylogenomics to clarify the concept of rice species, aid in the identification and use of rice germplasms, and support rice biodiversity. Abstract Rice (genus Oryza) is one of the most important crops in the world, supporting half of the world’s population. Breeding of high-yielding and quality cultivars relies on genetic resources from both cultivated and wild species, which are collected and maintained in seed banks. Unfortunately, numerous seeds are mislabeled due to taxonomic issues or misidentifications. Here, we applied the phylogenomics of 58 complete chloroplast genomes and two hypervariable nuclear genes to determine species identity in rice seeds. Twenty-one Oryza species were identified. Conspecific relationships were determined between O. glaberrima and O. barthii, O. glumipatula and O. longistaminata, O. grandiglumis and O. alta, O. meyeriana and O. granulata, O. minuta and O. malampuzhaensis, O. nivara and O. sativa subsp. indica, and O. sativa subsp. japonica and O. rufipogon.D and L genome types were not found and the H genome type was extinct. Importantly, we evaluated the performance of four conventional plant DNA barcodes (matK, rbcL, psbA-trnH, and ITS), six rice-specific chloroplast DNA barcodes (psaJ-rpl33, trnC-rpoB, rps16-trnQ, rpl22-rps19, trnK-matK, and ndhC-trnV), two rice-specific nuclear DNA barcodes (NP78 and R22), and a chloroplast genome super DNA barcode. The latter was the most reliable marker. The six rice-specific chloroplast barcodes revealed that 17% of the 53 seed accessions from rice seed banks or field collections were mislabeled. These results are expected to clarify the concept of rice species, aid in the identification and use of rice germplasms, and support rice biodiversity.

Search for cytoplasmic male sterility plants and its maintainer plants of carrots in Rogneda variety

Relevance. Hybrid seed production of carrots is carried out on a three-line basis, which suggests the presence of a male sterile maternal line and a fertile paternal line. For the reproduction of a male sterile line, a maintainer line is needed. The process of creating an isogenic pair of a manly sterile line – a maintainer line is of great complexity. As a maintainer line, it is necessary to use only a plant – a homozygote Cyt N msms for the core genes providing sterility, but with a normal cytoplasm. The purpose of the work is the creation of maintainer line for the sterility of carrots from the population of the Rogneda variety.Methods. Research were carried out: in 2016, at the experimental base of the Voronezh Vegetable Experimental Station (Voronezh Region); in 2017 - 2019, at the breeding center of All-Russian Research Institute of Vegetable Growing – branch of Federal State Budgetary Scientific Institution Federal Scientific Vegetable Center (Moscow Region). The material for the work was seed plants and roots of the Rogneda variety and hybrid, inbred, backcross progenies obtained from this population. Breeding methods: hybridization, inbreeding. Crosses used: simple direct and complex return (backcrosses), inbreeding.Results.Research revealed the possibility of searching for a maintainer line in the Rogneda variety. The P43f inbred progeny is potential line B, which maintains the CMS trait of the petaloid type at 100%. Of the 67 hybrid progenies, only P43st x P43f was left, in which all plants with male sterility. 65 hybrid progenies contained both sterile and fertile plants. Associated 65 inbred progenies had sterile and fertile plants, i.e. it makes no sense to try to obtain a maintainer line is needed. The process of creating an isogenic pair of a manly sterile line – a maintainer line from such fertile plants. Hybrid progeny of P4st x P4f had 100% fertile plants. The inbred progeny of P4f was represented only by fertile plants.

Individual variation in migratory behavior in a subarctic partial migrant shorebird

Migratory behavior can differ markedly amongst individuals within populations or species. Understanding the factors influencing this variation is key to understanding how current environmental changes might influence migratory propensity and the distribution and abundance of migratory species across their range. Here, we investigate variation in migratory behavior of the partially migratory Eurasian oystercatcher (Haematopus ostralegus) population breeding in Iceland. We use the resightings of color-ringed adults and stable isotopes to determine whether individuals migrate or remain in Iceland during winter and test whether individual migratory strategies vary in relation to sex, body size, and breeding location. We also explore individual consistency in migratory strategy and test whether assortative mating with respect to strategy occurs in this population. The proportion of migrants and residents varied greatly across breeding locations but not with respect to sex or body size. Individuals were consistent in migratory strategy between years and there was no evidence of assortative mating by migratory strategy. We use these findings to explore factors underlying the evolution and maintenance of partial migration at high latitudes.

THE USE OF CLASSICAL AND MODERN METHODS IN RAPESEED (BRASSICA NAPUS) BREEDING AT VNIIMK

Introduction. Rapeseed is a facultative autogamous plant; its percentage of cross-pollination is 10–50%, so rapeseed breeding engages the line and population breeding methods as well as the development of hybrids and all innovative research approaches.Material and methods. Among the main techniques used for the development of parent material and, eventually, cultivars at the Pustovoit Institute (VNIIMK) is the pedigree method (individual selection from intraspecific and interspecific hybrid populations, combined with inbreeding). Physical and chemical mutagenesis is also employed in rapeseed breeding at VNIIMK. The material with yellow-colored seed coat has been obtained by exposing rapeseed seeds to various doses of gamma rays (50, 100 and 150 kR). Seed treatment with chemical mutagens is primarily aimed at changing the fatty acid composition of oil.Results. Breeding achievements for winter and spring rapeseed, registered by VNIIMK in the State Register of Breeding Achievements of the Russian Federation over the past 15 years, are highly productive line cultivars with a seed yield of 4–5 t/ha for winter rapeseed, and 2–3 t/ha for spring rapeseed. Promising experimental interline hybrids, significantly exceeding the reference in seed yield (by 1.61–2.26 t/ha), have been developed. Yellowseeded lines, which exceed the black-seeded reference cv. ‘Tavrion’ in seed yield by 0.08–0.15 t/ha, have been selected. We developed the material with an oleic acid level of 78.9– 80.5%.