Current Breeding Efforts Research Articles

Mitigating cold stress in rice: a study of genotype performance and sowing time

Rice (Oryza sativa L.) is an essential food for half of the global population and is vital in maintaining global food security. Climate change, increasing population and recent incident of COVID pandemic has generated financial burden and threaten the global food security. Due to theses factors rice cultivation also has to face significant challenges. frequent weather changes pose a considerable challenge to agricultural planning, which was previously relaying on consistent seasonal variations. In this context, rice cultivation is particularly sensitive to cold, where its development and productivity inhibited by low temperatures (< 18 °C). Developing rice varietes with low temprature tolerence and good yield potential is one of the major goals of current breeding efforts of plant scientists. For this purpose, short duration and early rice varieties are most favorable to avoid cold stress and yield more in less number of days. this study was designed to investigate the effect of low temperatures on different rice varieties. the study was designed to identify low temprature tolerent genotypes with early and regular cultivation. For this, thirty-four genotypes were evaluated in two gorwing seasons (2018–2019) with four different sowing times. Statistically sowing time showed significant interaction between all yield contributing parameters. The data indicate that exposure to low temperatures during the reproductive phase prolongs the maturation period of the crop, also length of the panicle and the fertility of the spikelets drops, resulting in a significant decrease in the production of sensitive varieties. Some varieties are more sensitive to cold stress compared to others. In the Egyptian context, Giza176, Sakha104, and Sakha107 are recommended for early cultivation, while the genotypes Giza 179, Sakha101, Sakha104, and GZ 9730-1-1-1-1 are indicated for the normal cultivation period. The Sakha104 variety is particularly notable, as it is recommended for both purposes. In addition, the data obtained in this study provide valuable information for selecting rice varieties suitable for double cropping in the North Delta of Egypt. This study also contributes to the existing literature, providing insights into the resilience of rice cultivation in the face of climate change.

Six decades of soybean breeding in Ontario, Canada: a tradition of innovation

Soybean has been widely grown by Canadian farmers for more than 80 years, especially in southern Ontario. In recent decades, the Canadian growing region has expanded east and north. An average of 1% soybean yield improvement is achieved annually, thanks to efforts by public and private soybean breeding programs. However, to meet future food demands, an average 2.4% annual increase in soybean yield is required. Soybean breeders are mostly dealing with complex traits that are under control by several intrinsic and extrinsic factors, so sufficient information about past and current breeding efforts is required to modify future breeding programs accordingly. Here, we review public soybean breeding efforts over the past 25 years in southern Ontario, one of the most productive regions for Canadian soybean growers. Furthermore, we explain how recent advances could facilitate soybean breeding programs by reducing the time and cost and increasing selection accuracy in a large breeding population. Finally, we summarize future directions in three important sections, that is, multi-omics, environmental, and data-driven approaches, and provide a vision for future soybean breeding programs.

Key miRNAs and Genes in the High-Altitude Adaptation of Tibetan Chickens.

Tibetan chickens living at high altitudes show specific physiological adaptations to the extreme environmental conditions. However, the regulated base of how chickens adapt to high-altitude habitats remains largely unknown. In this study, we sequenced 96 transcriptomes (including 48 miRNA and 48 mRNA transcriptomes of heart, liver, lung, and brain) and resequenced 12 whole genomes of Tibetan chickens and Peng'xian yellow chickens. We found that several miRNAs show the locally optimal plastic changes that occurred in miRNAs of chickens, such as miR-10c-5p, miR-144-3p, miR-3536, and miR-499-5p. These miRNAs could have effects on early adaption to the high-altitude environment of chickens. In addition, the genes under selection between Tibetan chickens and Peng'xian yellow chickens were mainly related to oxygen transport and oxidative stress. The I-kappa B kinase/NF-kappa B signaling pathway is widely found for high-altitude adaptation in Tibetan chickens. The candidate differentially expressed miRNAs and selected genes identified in this study may be useful in current breeding efforts to develop improved breeds for the highlands.

Mediterranean White Lupin Landraces as a Valuable Genetic Reserve for Breeding.

Legumes crops are important for sustainable agriculture and global food security. Among them white lupin (Lupinus albus L.), is characterized by exceptional protein content of high nutritional value, competitive to that of soybean (Glycine max) and is well adapted to rainfed agriculture. However, its high seed-quinolizidine alkaloid (QA) content impedes its direct integration to human diet and animal feed. Additionally, its cultivation is not yet intensive, remains confined to local communities and marginal lands in Mediterranean agriculture, while adaptation to local microclimates restrains its cultivation from expanding globally. Hence, modern white lupin breeding aims to exploit genetic resources for the development of “sweet” elite cultivars, resilient to biotic adversities and well adapted for cultivation on a global level. Towards this aim, we evaluated white lupin local landrace germplasm from Greece, since the country is considered a center of white lupin diversity, along with cultivars and breeding lines for comparison. Seed morphological diversity and molecular genetic relationships were investigated. Most of the landraces were distinct from cultivars, indicating the uniqueness of their genetic make-up. The presence of pauper “sweet” marker allele linked to low seed QA content in some varieties was detected in one landrace, two breeding lines, and the cultivars. However, QA content in the examined genotypes did not relate with the marker profile, indicating that the marker’s predictive power is limited in this material. Marker alleles for vernalization unresponsiveness were detected in eight landraces and alleles for anthracnose resistance were found in two landraces, pointing to the presence of promising germplasm for utilization in white lupin breeding. The rich lupin local germplasm genetic diversity and the distinct genotypic composition compared to elite cultivars, highlights its potential use as a source of important agronomic traits to support current breeding efforts and assist its integration to modern sustainable agriculture.

Molecular characterization of two highly divergent Iranian johnsongrass mosaic virus isolates from Zea mays.

Iranian johnsongrass mosaic virus (IJMV, genus Potyvirus, family Potyviridae) is one of the most prevalent viruses causing maize mosaic disease in Iran. In this study, the complete genomes (9,618 and 9,543 nucleotides) of two highly divergent IJMV isolates (Maz2 and Maz3) were obtained from the metagenomic analysis of Zea mays RNAs using Illumina sequencing. The genome contained a single open reading frame (9,165 nucleotides) encoding a polyprotein of 3,054 amino acids, flanked by a 5'-untranslated region (UTR) of 216 and 143 nucleotides and a 3'-UTR of 237 and 235 nucleotides. A comparative analysis of the complete genome showed that IJMV-Maz2 and Maz3 had 85.99% nucleotide and 94.56% amino acid sequence identity with each other and shared 84.87-88.74% nt and 94.24-96.17% aa identity with those of two other IJMV isolates available in the GenBank. The coat protein of Maz2 and Maz3 showed 86.40-95.72% nt sequence identity (90.79-97.70% aa identity) to 12 other IJMV isolates available in GenBank. Our results indicated a relatively stable and conserved genomic composition with a low codon usage bias in all of the assayed IJMV coding sequences. Analysis of various population genetics parameters and distribution of synonymous and nonsynonymous mutations revealed that purifying selection pressure was the major force acting upon the IJMV genome. The outcome of the study provides valuable insights on the evolution of IJMV genome, for which there are few genome sequences available, and informs the current breeding efforts towards resistance for IJMV.

Reaching the highest shelf: A review of organic production, nutritional quality, and shelf life of kale (Brassica oleracea var. acephala)

Societal Impact StatementSince its inception in the early 20th century, organic agriculture has grown increasingly popular due to its focus on a holistic, environmentally friendly approach to crop production. However, it is comparatively limited in biomass production, disease management, nutritional quality, and postharvest treatment compared to conventional agriculture. These challenges carry over into kale production, the majority of which is certified organic. This article reviews organic kale production, morphology, and shelf life, focusing on nutrition and plant breeding. It explores the shortcomings of organic output and potential areas of study to enhance shelf life in organic kale while maintaining nutritional quality. Summary Organic production has grown exponentially over the past few decades in both acreage and popularity worldwide. This review focuses specifically on kale produced in the USA. However, regulations limiting synthetic inputs leave organic produce at a disadvantage compared to conventional agriculture in terms of biomass, nutritional quality, disease management, and postharvest treatment. Organic agriculture requires significant improvements to be a viable means of production for a growing population. Kale (Brassica oleracea var. acephala) is a “nutritional powerhouse” leafy green vegetable. The high concentration of vitamins, minerals, and prebiotic carbohydrates in a low‐calorie food makes kale an important crop for combatting obesity‐related non‐communicable diseases. However, the short shelf life of organic kale and inevitable fresh food waste make developing new kale cultivars with increased shelf life essential. This review article aims to (a) review kale morphology, consumer preference, and production, and (b) review nutritional quality, its effect on shelf life, and current breeding efforts of kale. Future research could focus on developing a kale breeding pipeline following suitable kale germplasm selection adapted to organic agriculture with both superior shelf life and improved nutritional quality.

Morphological characteristics and yield performance of mutant soybean [Glycine max (L.) Merr.] M6 genotypes in Jatinangor, Sumedang, West Java

Current breeding efforts in soybean largely focus on identifying genotypes with high seed yield and large seed size. Our study applied a mutation using 250 Gy Gamma-Ray Irradiation to soybean cv. Anjasari. The variability in the M1 generation was identified, and the planting was continued to M2 M3, M4, M5 until M6 generation. The objectives of this research were to evaluate mutant lines exhibiting a good performance in yield and morphological characteristics that can support the yield component in M6 generation. This research was conducted from January 2019 to May 2019 at Ciparanje Experiment Station, Faculty of Agriculture, Universitas Padjadjaran, Jatinangor, West Java. The experiment was arranged in a Randomized Completely Block Design with fifteen mutant soybean genotypes as treatments with two replications within each treatment. The results showed several genotypes produced higher yield and better agro-morphological characteristics. The genotypes MR-33, MR-4A, and MR-2A showed significantly higher number of total pods per plant. Meanwhile, the genotypes MR-35A, MR-37, MR-23, MR-36A, MR-3A, MR-29A MR-34A, MR-4A, MR-17, and MR-5A showed a higher value in weight of 100 seeds. The highest yield was observed in MR-29A and MR-23, which then will be used as the genotypes for multilocation test for stability.

Population structure of Nepali spring wheat (Triticum aestivum L.) germplasm

BackgroundAppropriate information about genetic diversity and population structure of germplasm improves the efficiency of plant breeding. The low productivity of Nepali bread wheat (Triticum aestivum L.) is a major concern particularly since Nepal is ranked the 4th most vulnerable nation globally to climate change. The genetic diversity and population structure of Nepali spring wheat have not been reported. This study aims to improve the exploitation of more diverse and under-utilized genetic resources to contribute to current and future breeding efforts for global food security.ResultsWe used genotyping-by-sequencing (GBS) to characterize a panel of 318 spring wheat accessions from Nepal including 166 landraces, 115 CIMMYT advanced lines, and 34 Nepali released varieties. We identified 95 K high-quality SNPs. The greatest genetic diversity was observed among the landraces, followed by CIMMYT lines, and released varieties. Though we expected only 3 groupings corresponding to these 3 seed origins, the population structure revealed two large, distinct subpopulations along with two smaller and scattered subpopulations in between, with significant admixture. This result was confirmed by principal component analysis (PCA) and UPGMA distance-based clustering. The pattern of LD decay differed between subpopulations, ranging from 60 to 150 Kb. We discuss the possibility that germplasm explorations during the 1970s–1990s may have mistakenly collected exotic germplasm instead of local landraces and/or collected materials that had already cross-hybridized since exotic germplasm was introduced starting in the 1950s.ConclusionWe suggest that only a subset of wheat “landraces” in Nepal are authentic which this study has identified. Targeting these authentic landraces may accelerate local breeding programs to improve the food security of this climate-vulnerable nation. Overall, this study provides a novel understanding of the genetic diversity of wheat in Nepal and this may contribute to global wheat breeding initiatives.

Food‐Grade Maize Composition, Evaluation, and Genetics for Masa‐Based Products

ABSTRACTMaize (Zea mays L.) masa (dough or flour that is soaked and cooked in an alkaline solution in the nixtamlization process) based products have been consumed by humans worldwide for thousands of years. Still, there is not a comprehensive understanding of the chemical and physical properties of maize that contribute to masa quality. Starches and proteins affect the alkaline processing of maize but are seldom discussed in a holistic way to understand their individual and combined effects on masa production, particularly in the context of the entire food system from breeding to evaluation to product development and production. In this review, the food‐grade maize production chain is described including current breeding efforts and grain evaluation methods. The compositions of starches and prolamin proteins are also discussed relative to their effect on masa properties. Understanding the interactions of grain endosperm components and final product quality of maize masa‐based products will allow for more efficient breeding and food processing operations in the future.

Genomic Analysis Reveals Pleiotropic Alleles at EDN3 and BMP7 Involved in Chicken Comb Color and Egg Production.

Artificial selection is often associated with numerous changes in seemingly unrelated phenotypic traits. The genetic mechanisms of correlated phenotypes probably involve pleiotropy or linkage of genes related to such phenotypes. Dongxiang blue-shelled chicken, an indigenous chicken breed of China, has segregated significantly for the dermal hyperpigmentation phenotype. Two lines of the chicken have been divergently selected with respect to comb color for over 20 generations. The red comb line chicken produces significantly higher number of eggs than the dark comb line chicken. The objective of this study was to explore potential mechanisms involved in the relationship between comb color and egg production among chickens. Based on the genome-wide association study results, we identified a genomic region on chromosome 20 involving EDN3 and BMP7, which is associated with hyperpigmentation of chicken comb. Further analyses by selection signatures in the two divergent lines revealed that several candidate genes, including EDN3, BMP7, BPIFB3, and PCK1, closely located on chromosome 20 are involved in the development of neural crest cell and reproductive system. The two genes EDN3 and BMP7 have known roles in regulating both ovarian function and melanogenesis, indicating the pleiotropic effect on hyperpigmentation and egg production in blue-shelled chickens. Association analysis for egg production confirmed the pleiotropic effect of selected loci identified by selection signatures. The study provides insights into phenotypic evolution due to genetic variation across the genome. The information might be useful in the current breeding efforts to develop improved breeds for egg production.

Evolutionary insights of Bean common mosaic necrosis virus and Cowpea aphid-borne mosaic virus.

Plant viral diseases are one of the major limitations in legume production within sub-Saharan Africa (SSA), as they account for up to 100% in production losses within smallholder farms. In this study, field surveys were conducted in the western highlands of Kenya with viral symptomatic leaf samples collected. Subsequently, next-generation sequencing was carried out to gain insights into the molecular evolution and evolutionary relationships of Bean common mosaic necrosis virus (BCMNV) and Cowpea aphid-borne mosaic virus (CABMV) present within symptomatic common bean and cowpea. Eleven near-complete genomes of BCMNV and two for CABMV were obtained from western Kenya. Bayesian phylogenomic analysis and tests for differential selection pressure within sites and across tree branches of the viral genomes were carried out. Three well–supported clades in BCMNV and one supported clade for CABMNV were resolved and in agreement with individual gene trees. Selection pressure analysis within sites and across phylogenetic branches suggested both viruses were evolving independently, but under strong purifying selection, with a slow evolutionary rate. These findings provide valuable insights on the evolution of BCMNV and CABMV genomes and their relationship to other viral genomes globally. The results will contribute greatly to the knowledge gap involving the phylogenomic relationship of these viruses, particularly for CABMV, for which there are few genome sequences available, and inform the current breeding efforts towards resistance for BCMNV and CABMV.

Genetic basis and the current breeding efforts for quality protein maize in Southern Africa

Maize (Zea mays L.) is deficient in essential amino acids, lysine and tryptophan. Opaque-2 maize mutant discovery that is high in lysine and tryptophan, offers an avenue for maize protein quality improvement. Quality protein maize (QPM), a product of the extensive development of the Opaque-2 mutant, is an affordable and viable option for overcoming the scourge of protein malnutrition in humans and monogastric livestock especially in sub-Saharan Africa. The objective of this review was to scrutinise the genetic basis of quality protein maize (QPM), and current breeding efforts, and propose potential uptake pathways for QPM products in southern Africa. The conventional QPM breeding methods are based on phenotypic selection to identify genotypes carrying the recessive Opaque-2 alleles. However, phenotypic selection is negatively influenced by the environment and has huge drain on resources such as time, money and labour, with low genetic gains. From this, marker assisted breeding methods are clearly the most efficient way of QPM breeding. Institutions such as the International Maize and Wheat Improvement Centre (CIMMYT) are currently employing molecular breeding in QPM breeding programmes so as to quicken and ease the process of QPM breeding. To date, a number of QPM varieties have been released and are being promoted using various pathways and policies.Key words: Opaque-2 gene, phenotypic selection, QPM, Zea mays L.

Resequencing of Common Bean Identifies Regions of Inter-Gene Pool Introgression and Provides Comprehensive Resources for Molecular Breeding.

Common bean ( L.) is the most important grain legume for human consumption and is a major nutrition source in the tropics. Because bean production is reduced by both abiotic and biotic constraints, current breeding efforts are focused on the development of improved varieties with tolerance to these stresses. We characterized materials from different breeding programs spanning three continents to understand their sequence diversity and advance the development of molecular breeding tools. For this, 37 varieties belonging to , (A. Gray), and L. were sequenced by whole-genome sequencing, identifying more than 40 million genomic variants. Evaluation of nuclear DNA content and analysis of copy number variation revealed important differences in genomic content not only between and the two other domesticated species, but also within , affecting hundreds of protein-coding genomic regions. A large number of inter-gene pool introgressions were identified. Furthermore, interspecific introgressions for disease resistance in breeding lines were mapped. Evaluation of newly developed single nucleotide polymorphism markers within previously discovered quantitative trait loci for common bacterial blight and angular leaf spot provides improved specificity to tag sources of resistance to these diseases. We expect that this dataset will provide a deeper molecular understanding of breeding germplasm and deliver molecular tools for germplasm development, aiming to increase the efficiency of bean breeding programs.

Genetic progress of spring wheat grain yield in various production regions of South Africa

Successful wheat production depends on several informed production decisions, including availing stable and high yielding cultivars. Periodic evaluation of the genetic gains in grain yield is a means of determining the effectiveness of current breeding efforts in increasing wheat productivity. Data collected from the Agricultural Research Council's Small Grain National Wheat Cultivar Evaluation program (NWCEP) over the period from 1998 to 2013 were used to estimate genetic gains in grain yield of irrigated spring wheat in South Africa. Compared with three control cultivars (ʻSST 822', ʻSST 876' and ʻKariega'), the estimated genetic gain in grain yield potential in the Eastern Highveld was approximately 0.82% y−1 for all entries and 1.17% y−1 for the highest yielding entries. In the Cooler Central areas, the genetic gain was 0.40% y−1 for all entries. In the Warmer Northern areas and KwaZulu-Natal province, there was yield stagnation over the years. Strong positive correlations of yield and hectolitre mass were observed, suggesting that much of the genetic yield gains over the period were achieved through increase in seed density. However, prospects of improving genetic yield gains in the country are high through the recently implemented end-point royalty system.

Physiological and transcriptomic analysis of responses to different levels of iron excess stress in various rice tissues

ABSTRACTIron (Fe) toxicity is a major nutritional disorder of plants and affects rice yield and production in rainfed and irrigated lowland rice grown in acid soils. Rice plants are reported to have exclusion and inclusion adaptation strategies for preventing damage from excess Fe. However, the molecular mechanisms behind the Fe toxicity response and the identities of the genes involved remain largely unknown. To reveal these mechanisms, we exposed rice plants to different levels of ferrous (Fe2+) excess treatment for 14 days and analyzed their growth, bronzing score, and mineral concentrations. Then, gene expression patterns in various tissues (roots, discrimination center [DC], stems, old leaves [OLs], and newest leaves [NLs]) in response to different levels of Fe excess (×1, ×10, ×20, ×50, and ×70 Fe) were examined using microarray analysis. Our results showed that the higher levels of Fe excess led to more Fe being preferentially translocated to OLs, thus avoiding Fe excess damage in the NL. We proposed three zones of Fe excess levels: the non-affected, affected, and dead zones. As an exclusion strategy, Fe uptake- and transport-related genes were suppressed in roots since in the non-affected zone. Roots are important for preventing Fe uptake to the plant body under Fe excess stress. As inclusion strategies, first, some genes highly induced in various tissues under Fe excess, such as OsNAS3, OsVIT2, and rice ferritin genes (OsFers), may be important for detoxification or isolation of excess Fe within the plant body. OsZIPs may contribute to the maintenance of zinc homeostasis. Second, the plant induces the expression of oxygen and electron transfer genes, cytochrome P450 family proteins, or some NAC-type transcription factors to avoid reactive oxygen species and abiotic stress caused by Fe excess in the affected zone. The plant may use similar Fe homeostasis mechanisms in the non-affected and affected zones in the NL and roots but employ different mechanisms in the OL, DC, and stem tissues. Our results will contribute to current screening and breeding efforts, which aim to develop Fe excess tolerance in diverse rice cultivars, thus increasing rice production in lowland fields.

How do helpers help? Helper contributions throughout the nesting cycle in the cooperatively breeding brown-headed nuthatch

Breeder investment in offspring reflects a trade-off between the benefits realized from current reproductive efforts and the benefits expected from future reproductive opportunities. When assisted by nonbreeding helpers that provide care for offspring, breeders may modify reproductive investments to minimize the costs of producing offspring, or in ways that maximize productivity and offspring survival. How helpers assist breeders can vary with different stages of reproduction, and how breeders alter investment in response to helpers may change depending on the stage of reproduction. We assessed how helpers contribute to reproduction and how breeders alter their investment in response to helper contributions in the cooperatively breeding brown-headed nuthatch (Sitta pusilla). We assessed helper contributions across three stages of reproduction: (1) nest excavation, (2) maternal egg production, and (3) nestling care and development at days 8–12 post-hatching, a period of rapid nestling growth. We also investigated how breeders responded to helper contributions and the relationship of helper behavior with breeders’ reproductive success. Helpers contributed to offspring care but not nest excavation. Breeders assisted by helpers did not alter investments in nest excavation, offspring production, or offspring care. As a result, offspring raised by cooperative groups received more food and weighed more. Nests with helpers were more likely to fledge at least one offspring, even when considering variation in territory characteristics and breeder experience. Results indicate breeders likely benefit from the favorable breeding conditions helpers provided for current breeding efforts, which influenced the quality of offspring produced and their likelihood of fledging in this study. Helpers may contribute to breeders’ reproductive effort during many stages of reproduction. The presence of nonbreeding helpers should therefore influence the investments made by breeders during different stages of breeding. Investment decisions in one stage should furthermore influence later investment decisions. We demonstrated that helpers assisted breeders primarily during the offspring rearing stage in brown-headed nuthatches (Sitta pusilla), a facultative cooperative breeder. Breeders with helpers maintained their level of investments in offspring similar to the investments documented for breeders without helpers. As a result, chicks in nests with helpers received more food and were heavier, and adults with helpers were more likely to fledge at least one young. Our results suggest that the combined effects of parental and helper investment provided benefits for current broods with potentially important survival consequences for offspring.

Target Amplicon Sequencing for Genotyping Genome-Wide Single Nucleotide Polymorphisms Identified by Whole-Genome Resequencing in Peanut.

Genome-wide genotyping data regarding breeding materials are essential resources for improving breeding efficiency, especially in plants with complex genomes with a high degree of polyploidy. Several current breeding efforts in cultivated peanut ( L.), which has a tetraploid genome, are devoted to developing high oleic acid cultivars. Genetic maps for such breeding programs have been developed using simple-sequence repeat (SSR) markers, the use of which requires time-consuming electrophoretic analyses. Next-generation sequencing (NGS) technology can overcome this technical hurdle. Initially, we attempted double-digest restriction site-associated DNA sequencing on peanut breeding materials used to develop high oleic acid cultivars. However, this method was not effective because few single nucleotide polymorphism (SNPs) were available because of low genetic diversity of the lines. The genome sequences of the probable diploid ancestors of cultivated peanut, Krapov. & W. C. Greg. and Krapov. & W. C. Greg., are available. Therefore, we next employed whole-genome resequencing analysis to obtain genome-wide SNP data. In this analysis, we observed large biases in the numbers and genomic positions of interspecific and intraspecific SNPs. For genome-wide genotyping, we selected a subset of SNPs covering the peanut genome as the targets of amplicon sequencing analysis. Using this technique, genome-wide genotypes of the breeding materials were easily and rapidly determined. The SNP information and analytic methods developed in this study should accelerate genetics, genomics, and breeding in peanut.

Sensory sacrifices when we mass-produce mass produce.

Plant breeders have been extremely successful at driving genetic improvements in crops. However, ‘improvements’ are truly a question of perspective. Over the last one-hundred years most plant genetic innovations have been driven by industry demand. Larger fruits, heavier yields, uniformity, increased resistance to disease and better shipping quality are just a few of the traits that have ensured profits on the farm and affordable food for consumers. However, these milestones have come at the expense of sensory qualities, which have been sacrificed in exchange for practical production objectives. With a base of industry-sufficient genetics, today’s breeders can now turn to the consumer for guidance in defining critical desires. New approaches to plant breeding start with the analysis of consumer preferences, and then merge them with modern genomics and analytical chemistry tools. The result is the next generation of crops that meet supply chain demands while presenting improvements in flavor, nutrition, color, aroma and texture. This review analyzes the approach of consumer-assisted selection as it has been applied to tomato and strawberry, two complementary annual crops that have been intensively bred to meet industry expectations. Current breeding efforts start with the consumer, with the objective of reclaiming lost sensory qualities.

INDUCTION OF TETRAPLOIDS IN ESCALLONIA SPP.

Escallonia is a genus of flowering shrubs, native to South-America. As for most woody ornamentals, current breeding efforts in Escallonia are low. In an attempt to enlarge the assortment and to introgress winter hardiness and a more compact growth habit, we performed in vitro polyploidization on Escallonia species. We collected 25 species and characterized their genome size, chromosome number, and leaf and flower parameters. Measured genome sizes of the collection varied between 1.01 and 1.31 pg/2C. In vitro polyploidization on E. rubra and E. rosea was more efficient when using oryzalin and trifluralin compared to colchicine. We obtained up to 56.7% E. rubra tetraploids using trifluralin (1 μM for 6 weeks) and 33.3% E. rosea tetraploids using oryzalin (150 μM for 3 days), compared to colchicine which only yielded 16.7% E. rubra (1000 μM for 3 days) and 3.3% E. rosea (2000 μM for 3 days) tetraploids. Short (2, 3 and 4 days) and chronic (6, 8 and 10 weeks) treatments on E. rubra displayed a higher polyploidization efficiency for trifluralin (28%) compared to oryzalin (18%). Ploidy doubled plantlets and diploid controls were acclimatized in the greenhouse for further morphological evaluation. The most efficient treatment was chosen to polyploidize other Escallonia species.

Genomic Analyses Reveal Potential Independent Adaptation to High Altitude in Tibetan Chickens.

Much like other indigenous domesticated animals, Tibetan chickens living at high altitudes (2,200-4,100 m) show specific physiological adaptations to the extreme environmental conditions of the Tibetan Plateau, but the genetic bases of these adaptations are not well characterized. Here, we assembled a de novo genome of a Tibetan chicken and resequenced whole genomes of 32 additional chickens, including Tibetan chickens, village chickens, game fowl, and Red Junglefowl, and found that the Tibetan chickens could broadly be placed into two groups. Further analyses revealed that several candidate genes in the calcium-signaling pathway are possibly involved in adaptation to the hypoxia experienced by these chickens, as these genes appear to have experienced directional selection in the two Tibetan chicken populations, suggesting a potential genetic mechanism underlying high altitude adaptation in Tibetan chickens. The candidate selected genes identified in this study, and their variants, may be useful targets for clarifying our understanding of the domestication of chickens in Tibet, and might be useful in current breeding efforts to develop improved breeds for the highlands.