Future Cultivars Research Articles

Predicting superior crosses in winter wheat using genomics: A retrospective study to assess accuracy

AbstractIn plant breeding, selecting cross‐combinations that are more likely to result in superior lines for cultivar development is critical. This step, however, is subjective with decisions being based on available genomic and phenotypic data for prospective parents. Genomic prediction (GP) provides new opportunities to accelerate genetic gain for a target trait by identifying superior crosses through simulation of progeny performance. In this context, this study deployed GP using the phenotype and genotype of potential parents to predict the progeny genetic variance (VG) and means of overall, inferior 10%, and superior 10% (μ, μip, and μsp, respectively). This retrospective experimental design investigated whether the crosses that produced superior soft red winter wheat breeding lines would have been made if progeny simulations had guided crossing decisions of breeding programs. Here, data from historical wheat breeding lines were used to train GP models and predict VG and means for yield, test weight, heading date, and plant height for all combinations of 217 parents. Predicted and observed data for 670 lines derived from biparental crosses were compared to assess the accuracy of progeny simulations, and low‐to‐moderate prediction accuracy was observed for the four traits (0.25–0.52). Of the pedigrees that produced lines that were selected and advanced into later stage nurseries, 76% were predicted to give rise to progeny with above‐average yield. The moderate correlation found between predicted progeny means and observed line per se performance justifies using cross‐combination prediction as a tool to reduce crossing number and focus on segregating populations that harbor future cultivars.

Evaluation of Some Popular Rice Varieties of Bangladesh for Physical and Cooking Quality Properties

Rice is the primary staple meal in many parts of the world. Therefore, both consumers and producers must pay close attention to the physical and cooking characteristics of grains. The present study was conducted to evaluate the physical and cooking quality characters in twenty popular Bangladeshi boro rice genotypes along with one japonica rice genotype. A high degree of significant variation was observed for all the characters studied. Genotypes BRRI dhan55, BR16, BRRI dhan57, BINA dhan-6 and BINA dhan-14 has the maximum length of grain before cooking (L1). BRRI dhan36, BRRI dhan57, BRRI dhan55 and BINA dhan-6 were the best performer in terms of grain length after cooking (L2). BRRI dhan57 and BRRI hybrid dhan1 were best for width of grain before cooking (W1). BRRI dhan57, BRRI dhan29 and BRRI dhan36 were exhibited minimum width of grain after cooking (W2). Yukihikari, BRRI hybrid dhan3 and BRRI dhan36 were best for grain elongation ratio. Highest grain length/width ratio before cooking (L1/W1) was observed in genotype BRRI dhan57, BRRI hybrid dhan1 and BINA dhan-14. The highest grain length/width ratio after cooking (L2/W2) was recorded in genotype BRRI dhan57 and BRRI dhan36. Best genotype for percent water uptake (WU %) after cooking was BRRI dhan28 (180%). The best genotypes for solid in cooking water (SCW) were BRRI dhan36 (0.897%), BRRI dhan28 (0.956%), Yukihikari (1.043%) and BRRI dhan29 (1.048%), respectively. The prominent performer genotypes for CT were BRRI dhan58 (18.38 minutes) followed by BR 14 (19.12 minutes), BRRI dhan28 (20.00 minutes) and BRRI dhan57 (19.82 minutes). Best genotypes for amylase content (AC) BRRI dhan28 (24.93%), BRRI dhan55 (24.91%), BRRI dhan59 (24.90%). Most of the rice genotypes had found low cooking time (GT) except BRRI dhan57, BRRI dhan59, Yukihikari which shows intermediate gelatinization temperature (GT). The comparative information about physical and cooking qualities of rice might be used as reference to develop high grain quality rice cultivars in future. Res. Agric. Livest. Fish. Vol. 11, No. 1, April 2024: 35-45

Genotypic Variation in Agronomic Traits and Molecular Markers among Chinese Luobuma (Apocynum spp.) Germplasm Accessions

Apocynum spp., known as Chinese Luobuma species, are perennial herbaceous plants that not only have good ecological characteristics, such as drought resistance, salt resistance, freezing resistance, high-temperature resistance and wind sand resistance, but also have good medicinal and textile value. However, studies on the genetic variation in Chinese Luobuma are rare. In this study, the genotypic variation in the agronomic traits and molecular markers among eight germplasm accessions (referred to as genotypes) of Apocynum spp. was investigated. The accessions were evaluated at two locations in China, Altay and Yuzhong, during a three-year period. Analysis of the variance in yield-related traits revealed significant genotypic variation (p < 0.05) among the eight genotypes at the early flowering and full flowering stages. There were also significant (p < 0.05) genotype × year and genotype × location × year interactions for all the traits except leaf dry weight. In comparison to those evaluated at Yuzhong, the plant height, number of branches, leaf dry weight and stem dry weight at the early flowering stage were greater in Altay, with averages of 991.0 mm, 5.52, 26.41 g and 25.35 g, respectively. There were significant (p < 0.05) differences among genotypes in terms of the quality traits measured at the early and full flowering stages. The crude protein and crude fat content for each genotype at different locations at the early flowering stage in different years ranged from 8.64 to 10.07%. The average flavone (FLA) content was 2.31 mg/100 g. Principal component analysis (PCA) revealed that the G1 genotype in Altay had a higher neutral detergent fiber content and leaf dry weight, and the G2 genotype had a larger stem thickness, branch number and stem-to-leaf ratio. Five DNA sequences, ITS, matK, psbA-trnH, rbcL and trnL-F, were selected for analysis of the molecular variance in Chinese Luobuma. Analyses of molecular variance (AMOVA) based on the nuclear DNA sequences and chloroplast DNA sequences showed that most of the variation occurred within species. Our study indicated the significant genetic variation in Chinese Luobuma for future cultivar domestication. Genotypes with high leaf dry weights and many branches are beneficial for tea production, while tall plants with long internode lengths are valuable for the production of hemp.

Mozambican Coffea accessions from Ibo and Quirimba Islands: identification and geographical distribution.

Mozambique does not have a tradition of farming Coffea arabica or Coffea canephora, the two species that dominate the worldwide coffee market. However, native coffee plants have been growing spontaneously and in some cases cultivated in the Ibo and Quirimba islands in the north of the country and Inhambane province in the south. Historically there has been confusion over the precise taxonomic classification of these indigenous coffee plants, with different botanists identifying the species as C. racemosa, C. zanguebariae or various synonyms of both. The present research aims to clarify the subject and provide new information on these little-described coffee species which may prove valuable as new breeding material for future cultivars, something that is sorely needed to face the present and future challenges of coffee production. Leaf samples were collected from 40 accessions from Ibo Island, Quirimba Island and Inhambane province. The samples were sequenced by whole-genome technology and WGS reads were filtered to identify relevant SNP variants. Diversity among the samples was assessed by PCA, and a phylogenetic tree including several Coffea species was built using additional data available in public databases. Experimental data confirm the presence of C. zanguebariae as the only coffee species present in both Ibo and Quirimba Islands, while it appears that C. racemosa is exclusive to the southern Inhambane province. The present research provides the most detailed analysis so far on the genetic identity of the traditional Mozambican coffee crops. This is the prerequisite for undertaking further scientific studies on these almost unknown coffee species and for starting agronomic development programs for the economic revival of Ibo and Quirimba islands based on coffee cultivation. Furthermore, these species could provide much-needed genetic material for the breeding of new hybrids with the two main commercial coffee species.

Diallel Crosses of Cotton (Gossypium hirsutum L.)—Enhancement of Fiber Properties in Future Cultivars for Burkina Faso

The market value of cotton in exporting countries, such as Burkina Faso, depends on the quality of major fiber properties. A lack of variation among the genetic resources available in Burkina Faso hinders breeding progress to meet fiber quality demands in future cultivars. F1 populations from a half diallel crossing scheme between lines developed at Texas A&M AgriLife cotton breeding program at Lubbock and germplasm accessed from Burkina Faso were evaluated for fiber property enhancement. Crosses exclusively within common origin materials did not result in highly enhanced hybrids. Hybrids within American materials expressed significant SCA effects undesirable for future cultivars in Burkina Faso. Five hybrids within the Burkina Faso material expressed significant SCA effects: two of them implicating FK37 as the better parent in transmitting superior targeted fiber traits to its progenies. Hybrid FK37xE9 significantly enhanced UHML, Str, UI and SFI but not Mic and Rd. Inter-program hybrids with at least one significant SCA effect were crosses with female American lines and male Burkina Faso parents. Hybrids E53x16-2-216FQ, E53x15-10-610-7 and E32x15-10-610-7 showed significantly improved Str and UI for the most economically important traits, which also include Mic, UHML, SFI, Rd and +b. Together, the GCA and SCA effects, heritability and correlations showed more additive than non-additive gene actions. Therefore, knowledge of the best combiners and hybrids could be used in the cultivar development process to enhance value with improved fiber characteristics.

Holistic approach to ascertain genetic variability and responsive trait selection for different heat regimes of central India via field screening of wheat recombinant inbred lines

AbstractHigh temperature affects wheat yield severely. This study aimed to explore the variation and recognition of heat responsive traits, to enhance wheat productivity in high temperature stress condition. The recombinant inbred lines were developed by crossing of released wheat variety MACS2496 (heat sensitive) and WH730 (heat tolerant). The experiments were conducted into 2 years at three locations of two planting conditions (heat and terminal heat stress). Combined analysis of variance shows significant variations among all the studied traits at individual location, year and planting conditions. The phenological and yield component traits were highly influenced by environment under terminal heat stress condition. Days to heading and thousand kernel weight coupled with high heritability and high genetic advance per cent of mean in heat and terminal heat stress environments. In heat and terminal heat stress planting conditions, tiller number per plant, kernels per spike, kernel weight per spike and thousand kernel weight confirm positive relationship with grain yield per plant by correlation and principal component analysis. Path and multiple regression analysis accomplish that tiller number per plant, kernel weight per spike, kernel per spike and thousand kernel weight were identified as the key contributor towards grain yield per plant in heat and terminal heat stress environment. Thus, all‐inclusive approaches demonstrated that the promising traits deliver a framework to develop heat tolerant cultivars in future.

Omics for Elucidating Heat Stress Tolerance Mechanisms in Wheat: A Review Update

For the vast majority of people on earth, wheat is a primary staple food crop. It is one of the most vulnerable crops, the production of which significantly suffers from the harmful effects of climate change. As the predicted increase in global temperature is supposed to jeopardize production, wheat improvement towards heat stress-resilience has gained pivotal importance. The large and complex allohexaploid wheat genome represents a genetic puzzle, where deciphering any trait-genetics is always challenging. Fortunately, the advancement in the ‘omics’ approach has paved the way for solving these issues in a multidisciplinary convergent manner. The approach has significantly contributed towards the complex molecular mechanisms of the heat stress tolerance in wheat. In the recent past, salient attainments have been observed in exploring heat tolerance mechanisms in wheat addressed through omics technologies. All these approaches have identified some of the key regulators behind this complex trait, the conglomeration of which is definitely promising for achieving heat tolerant cultivars. Besides, the epigenetic regulation of this important trait as well as the significant achievements in developing heat tolerant lines through a transgenic approach has been enumerated. This summarized review of an issue of global importance should enlighten the understanding of the complex regulation of heat tolerance mechanism in wheat, which is a prerequisite for the development of stable heat tolerant wheat cultivars in near future. Here we discussed current research on the genetic and molecular variables that alter one's ability to tolerate heat, including the effects of epigenetic regulation. At the end, we concluded the review by discussing integrative methods for enhancing heat tolerance through the use of current germplasm, such as contemporary cultivars, landraces, and related species.

Assessment of diverse cicer milkvetch (Astragalus cicer L.) germplasm for agro-morphological traits under a stockpiling system

Cicer milkvetch ( Astragalus cicer L.) is a non-bloating perennial forage legume suitable for stockpiled grazing in the fall because of its rapid regrowth and high nutritive value. Genetically diverse germplasm are needed for the development of improved cicer milkvetch cultivars that can provide consistent production across variable climatic conditions. The objective of this research was to assess the diversity and relationship of 27 cicer milkvetch populations to inform the selection of populations for future cultivars that have superior agro-morphological traits during summer and fall growth. A completely randomized field trial was established in 2019 near Clavet, Saskatchewan. In 2020 and 2021, forage dry matter yield (DMY), maximum stem length, leaf number per stem, rhizome spread, and stem density were recorded on 27 populations of cicer milkvetch in late June at a first harvest and mid-October at a stockpile harvest. All five traits were different ( p < 0.05) among the populations at both harvests except for leaf number per stem in late June. Principal component analysis identified that the first three principal components described 89% of the variation in agro-morphological traits at the first and stockpile harvests. Of the agro-morphological traits, maximum stem length had the greatest correlation with forage DMY at the first harvest ( r = 0.69) and stockpile harvest ( r = 0.6). Our research demonstrates that there is a high morphological diversity among cicer milkvetch populations, and plant introductions, PI 362266, PI 576963, PI 440143, and PI 362254 could be used as novel genetic resources for the development of climate-resilient cultivars.

Assessment of Alfalfa Populations for Forage Productivity and Seed Yield Potential under a Multi-Year Field Trial

Alfalfa is the most important forage legume in the production of voluminous fodder. Although not primarily produced for its seeds, the seed yield is still important for the recognition and commercial viability of the cultivars on the market. Creating a cultivar of superior yield and forage quality with satisfactory seed production is one of the biggest challenges for alfalfa breeders and seed producers. The objective of this study was to determine forage and seed yields of 19 newly developed alfalfa experimental populations (ABP 1–19) of the Agricultural Institute Osijek during a long-term research period (2014–2018) in different climatic conditions. Significant differences were found between ABPs and years for forage and seed yields. Three-year (2014–2016) average green mass yield ranged from 68.41 t ha–1 (ABP 6) to 78.05 t ha–1 (ABP 19) and dry matter yield from 13.73 t ha–1 (ABP 6) to 15.30 t ha–1 (ABP 18). The average two-year (2017–2018) seed yield varied from 150.78 kg ha−1 (ABP 9) to 335.35 kg ha−1 (ABP 7). Annual forage yield significantly increased from the year of establishment to the second and third growing seasons of alfalfa. The highest average annual yield of green mass (90.24 t ha−1) was achieved in 2015, dry matter yield (17.62 t ha−1) in 2016 and the seed yield (394.17 kg ha−1) in 2017. During the researched period there was a considerable decreasing trend in forage yield from the first to the last cut, except in the year of the alfalfa establishment. Several alfalfa populations (ABP 19, 8, 14) superior in all analyzed traits were identified, and they represent top performing materials with the potential for developing and releasing cultivars in the near future. Populations with high yields of green mass and dry matter (ABP 12, 18, 1) and seed yield (ABP 7, 4) were also detected and represent valuable genetic material to improve our alfalfa breeding program.

Effect of boron deficiency on the photosynthetic performance of sugar beet cultivars with contrasting boron efficiencies.

Boron (B) deficiency severely affects the quality of sugar beet production, and the employment of nutrient-efficient varieties for cultivation is a crucial way to solve environmental and resource-based problems. However, the aspect of leaf photosynthetic performance among B-efficient sugar beet cultivars remains uncertain. The B deficient and B-sufficient treatments were conducted in the experiment using KWS1197 (B-efficient) and KWS0143 (B-inefficient) sugar beet cultivars as study materials. The objective of the present study was to determine the impacts of B deficiency on leaf phenotype, photosynthetic capacity, chloroplast structure, and photochemical efficiency of the contrasting B-efficiency sugar beet cultivars. The results indicated that the growth of sugar beet leaves were dramatically restricted, the net photosynthetic rate was significantly decreased, and the energy flux, quantum yield, and flux ratio of PSII reaction centers were adversely affected under B deficiency. Compared to the KWS0143 cultivar, the average leaf area ratio of the KWS1197 cultivar experienced less impact, and its leaf mass ratio (LMR) increased by 26.82% under B deficiency, whereas for the KWS0143 cultivar, the increase was only 2.50%. Meanwhile, the light energy capture and utilization capacity of PSII reaction centers and the proportion of absorbed light energy used for electron transfer were higher by 3.42% under B deficiency; KWS1197 cultivar managed to alleviate the photo-oxidative damage, which results from excessive absorbed energy (ABS/RC), by increasing the dissipated energy (DIo/RC). Therefore, in response to B deprivation, the KWS1197 cultivar demonstrated greater adaptability in terms of morphological indices and photosynthetic functions, which not only explains the improved performance but also renders the measured parameters as the key features for varietal selection, providing a theoretical basis for the utilization of efficient sugar beet cultivars in future.

RicePedigree: Rice Pedigree Database for Documentation and Assistance in Rice Breeding

For the purpose of breeding documentation, researchers and breeders kept handwritten records of the breeding history, including parental information and breeding methods. The cultivars were used again as parents for further breeding, and modern cultivars of rice have a wide range of alleles from many generations of parents and ancestors. To understand such a breeding history, it is necessary to ask around for relevant information, which is then usually documented in Excel or Word by multiple breeders or breeding institutes. Here, we constructed RicePedigree, which contains the breeding history of rice based on the documents provided by the Rural Development Administration (RDA) in Korea. We devised a simple method for collecting a breeding history and storing it in a database. RicePedigree is a web-based application on the database that facilitates researchers’ and breeders’ utilization of the breeding history of rice. Based on the query cultivar name, it will return a hierarchical tree of breeding histories and a list of cultivars and breeding lines that contain query cultivars in their breeding histories. This app would be a good way to review and keep track of information about current and future cultivars.

The Effects of Elevated Tropospheric Ozone on Carbon Fixation and Stable Isotopic Signatures of Durum Wheat Cultivars with Different Biomass and Yield Stability.

Tropospheric ozone (O3) enrichment caused by human activities can reduce important crop yields with huge economic loss and affect the global carbon cycle and climate change in the coming decades. In this study, two Italian cultivars of durum wheat (Claudio and Mongibello) were exposed to O3 (80 ppb, 5 h day-1 for 70 consecutive days), with the aim to investigate the changes in yield and biomass, ecophysiological traits, and stable carbon and nitrogen isotope values in plants, and to compare the stable isotope responses under environmental stressors. Both cultivars showed a relative O3 tolerance in terms of photosynthetic performance, but in cultivar Mongibello, O3 was detrimental to the grain yield and plant biomass. The δ13C values in the leaves of plants identified that the impact of O3 on CO2 fixation by RuBisCO was dominant. The δ15N value showed significant differences between treatments in both cultivars at seven days from the beginning of the exposure, which could be considered an early indicator of ozone pollution. Under increasingly frequent extreme climates globally, the relationships among stable isotope data, ecophysiological traits, and agronomic parameters could help breed future cultivars.

Comparative Quality Assessment of Five Bread Wheat and Five Barley Cultivars Grown in Romania.

Cereals whole grains contain vitamins, phytochemicals, antioxidants, resistant starch, and minerals with potential benefits to human health. The consumption of whole grains is correlated with a lowered risk of the most important chronic diseases, including type II diabetes, cardiovascular diseases, and some cancers. This study aimed to characterize and evaluate the content of five cultivars of wheat (Triticum aestivum L.) and five cultivars of barley (Hordeum vulgare L.) obtained by conventional plant breeding using crossing and selection methods. The novelty and the purpose of this research was to quantitatively and qualitatively analyze these ten cultivars from Romania and to show the importance of, and the changes produced by, crossing and selection methods when these are aimed at the physiological or morphological development of the cultivars. Studies based on gluten dosing; spectrophotometry using Bradford, fructan and protein dosing; Kjeldahl protein dosing; GC-MS/MS-protein and amino acid dosing; and identification of protein fractions using polyacrylamide gel electrophoretic method were conducted. This study demonstrates the possibility of developing future cultivars using conventional methods of improvement to modify the content and composition of nutrients to increase their health benefits.

Understanding variation in oleic acid content of high-oleic virginia-type peanut

Contamination at the FAD2B locus due to inadequate screening protocols is the primary cause of sporadic, insufficient oleic acid content in Virginia-type peanut. The high oleic trait in peanut is conditioned by loss-of-function mutations in a pair of homeologous enzymes and is well known to improve the shelf life of peanut products. As such, the trait is given high priority in current and future cultivars by the North Carolina State University peanut breeding program. For unknown reasons, high oleic cultivars and breeding lines intermittently failed to meet self-imposed thresholds for oleic acid content in internal testing. To determine why, a manual seed chipper, crude DNA isolation protocol, genotyping assays for both mutations, and a web-based SNP calling application were developed. The primary cause was determined to be contamination with normal oleic seeds resulting from inadequate screening protocols. In order to correct the problem, a faster screening method was acquired to accommodate a higher oleic acid threshold. Additionally, results showed the mutation in one homeolog is fixed in the program, dig date had no significant effect on oleic acid content, and minor modifiers segregating within the program explained 6% of the variation in oleic acid content.

Diallel Crosses of Cotton (Gossypium hirsutum L.) from Burkina Faso and Texas A&M AgriLife Research—1-Analysis of Agronomic Traits to Improve Elite Varieties from Burkina Faso

Cotton breeding progress stagnation, changing production conditions, and continued high fiber quality demands are challenging the cotton industry in Burkina Faso. The F1 populations developed by half diallel crosses between germplasm from Texas A&M AgriLife Research and Burkina Faso were evaluated for several agronomic traits. The aim was to identify the most promising parents and hybrids for further varietal improvement. Three AgriLife parents helped improve the most important targeted traits. Parent 15-3-416 reduced days to 50% flowering (−3.14 days) and shortened plant height (−22.25 cm) in hybrids while 16-2-216FQ improved their fiber percentage (+2.68%). Hybrids with Burkina Faso elite cultivar E32 as male parent and the three best AgriLife parents as the females showed good specific combining ability (SCA). FK37 × 15-10-610-7 and FK64 × 15-10-610-7 showed heterosis for earliness by reducing, respectively, days to 50% flowering (−4.27 days) or days to 50% boll opening (−3.95 days) below parent means. E32 × 16-2-216FQ and FK64 × 16-2-216FQ increased fiber percentage by +1.75% and +2.06%, respectively. FK64 × 15-3-416 increased seed index (SI) (+0.62 g) and fiber percentage (+1.19%), while maintaining other traits at the parents’ average levels. E32 × 15-3-416 showed the most heterosis for desired improvements, reducing days to 50% flowering (−4) and increasing the number of bolls/vegetative branch (+3.05), number of bolls/fruiting branch (+6.38), number of bolls/plant (+13.49), boll weight (+1.53 g), SI (+0.40 g), and fiber percentage (+1.18%). Inter-program crosses show the potential to enhance genetic diversity in Burkina Faso’s breeding program. Subsequent selection methods must be carefully applied considering the Burkina Faso breeding objectives for future cultivars.

Identification of Putative Markers of Non-infectious Bud Failure in Almond [Prunus dulcis (Mill.) D.A. Webb] Through Genome Wide DNA Methylation Profiling and Gene Expression Analysis in an Almond × Peach Hybrid Population.

Almond [Prunus dulcis (Mill.) D.A. Webb] is an economically important nut crop susceptible to the genetic disorder, Non-infectious Bud Failure (NBF). Despite the severity of exhibition in several prominent almond cultivars, no causal mechanism has been identified underlying NBF development. The disorder is hypothesized to be associated with differential DNA methylation patterns based on patterns of inheritance (i.e., via sexual reproduction and clonal propagation) and previous work profiling methylation in affected trees. Peach (Prunus persica L. Batsch) is a closely related species that readily hybridizes with almond; however, peach is not known to exhibit NBF. A cross between an NBF-exhibiting ‘Carmel’ cultivar and early flowering peach (‘40A17’) produced an F1 where ∼50% of progeny showed signs of NBF, including canopy die-back, erratic branching patterns (known as “crazy-top”), and rough bark. In this study, whole-genome DNA methylation profiles were generated for three F1 progenies exhibiting NBF and three progenies considered NBF-free. Subsequent alignment to both the almond and peach reference genomes showed an increase in genome-wide methylation levels in NBF hybrids in CG and CHG contexts compared to no-NBF hybrids when aligned to the almond genome but no difference in methylation levels when aligned to the peach genome. Significantly differentially methylated regions (DMRs) were identified by comparing methylation levels across the genome between NBF- and no-NBF hybrids in each methylation context. In total, 115,635 DMRs were identified based on alignment to the almond reference genome, and 126,800 DMRs were identified based on alignment to the peach reference genome. Nearby genes were identified as associated with the 39 most significant DMRs occurring either in the almond or peach alignments alone or occurring in both the almond and peach alignments. These DMR-associated genes include several uncharacterized proteins and transposable elements. Quantitative PCR was also performed to analyze the gene expression patterns of these identified gene targets to determine patterns of differential expression associated with differential DNA methylation. These DMR-associated genes, particularly those showing corresponding patterns of differential gene expression, represent key targets for almond breeding for future cultivars and mitigating the effects of NBF-exhibition in currently affected cultivars.

GmBICs Modulate Low Blue Light-Induced Stem Elongation in Soybean.

Blue-light inhibitors of cryptochromes (BICs) promote hypocotyl elongation by suppressing the activity of cryptochromes in Arabidopsis. Nevertheless, the roles of BICs in other plant species are still unclear. Here we investigate their functions by genetic overexpression and CRISPR/Cas9 engineered mutations targeting the six GmBIC genes in soybean. We showed that the GmBICs overexpression (GmBICs-OX) lines strongly promoted stem elongation, while the single, double, and quadruple mutations in the GmBIC genes resulted in incremental dwarfing phenotypes. Furthermore, overexpression of GmBIC2a abolished the low blue light (LBL)-induced stem elongation, demonstrating the involvement of GmBICs in regulating cryptochrome-mediated LBL-induced shade avoidance syndrome (SAS). The Gmbic1a1b2a2b quadruple mutant displayed reduced stem elongation under LBL conditions, which was reminiscent of the GmCRY1b-OX lines. Taken together, this study provided essential genetic resources for elucidating GmBICs functional mechanisms and breeding of shade-tolerant soybean cultivars in future.

Changes in soybean cultivars released over the past 50\xa0years in southern Brazil

On-farm soybean yield has increased considerably in the last 50 years in southern Brazil, but there is still little information about how selection and breeding for yield increase has changed the agronomic attributes of cultivars. The objectives of this study were to evaluate the changes in soybean yield, seed oil and protein concentration, and changes in plant attributes that might be associated with yield improvement of 26 soybean cultivars released over the past 50 years in southern Brazil, sown simultaneously in a common field environment for two growing seasons. The average rate of yield gain was 45.9 kg ha−1 yr−1 (2.1% ha−1 yr−1), mainly due increased seed number per area and harvest index. Over year of cultivar release, cultivars became less susceptible to lodging, as well as plant mortality reduced. Meanwhile, the seed oil concentration increased, and seed protein concentration decreased, which could have negative consequences for soybeans use and requires further attention for breeding of future cultivars. Breeders have successfully contributed to the annual rate of soybean yield increase in southern Brazil. By our results, as well as the official on-farm production data, there is no evidence of soybean yield reaching a plateau in the near future in southern Brazil.

Genetic progress in cotton lint and yield components in Argentina

The Argentinian cotton (Gossypium hirsutum L.) breeding program was established in 1923 and since then it has released more than 40 commercial cultivars of cotton and numerous germplasm lines. Genetic progress studies have been used to evaluate the historical enhancement of different traits and to provide insights into possible improvements in future cultivars. In this context, the present study aims to estimate the genetic progress for lint yield (LY) and its components among cotton cultivars released in Argentina since 1965 throughout different environmental conditions and to determine correlations among agronomic traits. This study was conducted over a 2-year period and included 20 cotton cultivars grown in four different environments through different sowing dates. Genetic progress in LY was 3.24 kg.ha−1.y−1 with no differences among environments. The LY improvement was accompanied by a significant increase in seed cotton yield (SCY), lint percentage (LP), number of boll. m−2 (NB) and lint.seed−1 (LS). The environment was the dominant factor governing LY and its main components, except for LP where genotype was the dominating factor. Pearson correlation showed that LY, SCY, BN, boll weight, lint.boll-1, number seed.boll-1, and seed index were positively correlated. The information obtained from this study would be an important tool for crop management and breeding programs for high yielding cotton.

THE BLACKBERRY BREEDING PROGRAM OF “EMBRAPA CLIMA TEMPERADO”: AN UPDATE

<p><strong>Background</strong>: In terms of breeding perennial plants, the Embrapa's blackberry breeding program is relatively recent. It started between the end of the 1970s and beginning of the 1980s with a very limited number of cultivars plus a fairly good number of seeds from hybridizations made at the University of Arkansas, USA. <strong>Objective</strong>:<strong> </strong>this paper aim to present, in a summarized way, the current stage and recent achievements regarding the top priorities of the breeding program <strong>Methodology: </strong>Controlled hybridizations is the main method used and adaptation to mild winters conditions besides a higher ratio (sugar/acid contents) are among the main objectives. <strong>Results: </strong>Other objectives include high productivity, large size and firm fruits, good post-harvest conservation, erect, thornless canes and harvest period at different time of ‘Tupy,’ the most important one, in Brazil. <strong>Implications:</strong> It is believed that in the coming years, the Brazilian market will learn to like fresh blackberry, mainly considering the release of ‘BRS Cainguá’ and others that hopefully will follow. <strong>Conclusion: </strong>The present status of the program and achievements related to the main goals are discussed. Advanced selections with potential to become a future cultivar are briefly described, emphasizing next probable releases.</p>