High-yielding Cultivars Research Articles

Rapid Effect of Nitrogen Supply for Soybean at the Beginning Flowering Stage on Biomass and Sucrose Metabolism

Nitrogen application at the beginning flowering stage (R1 stage) increased the soybean grain yield, however, the rapid effect of enriched nitrogen at R1 growth stage on soybean dry matter accumulation and sugar metabolism is still unclear. Continuous high nitrogen (CHN), Continuous low nitrogen (CLN), Enriched nitrogen supply at R1 stage (ENS) treatments were applied on two soybean cultivars (Liaodou11, Liaodou14), to investigate the effect of enriched nitrogen on plant biomass accumulation and sucrose metabolism. After 12 h of ENS treatment, the root/shoot rate of both cultivars were lower than that of CLN, but at 24 h it was no significant difference between ENS and CLN. Enriched N at R1 stage, soybean kept a balance of sucrose synthesis and decomposition in leaf by affecting sucrose synthetase (SS) and sucrose phosphate synthase (SPS) activities. Under N limitation condition the plant dry matter accumulation supported root growth priority. Enriched N at R1 stage resulted in the rapid shoot biomass accumulation. In high yield cultivar, the shoot growth was priority to root growth, the common yield cultivar was on the contrary. Our result suggest that enrich N at R1 stage resulted in the accumulation of biomass in shoot rapidly.

Temporal and Spectral Optimization of Vegetation Indices for Estimating Grain Nitrogen Uptake and Late-Seasonal Nitrogen Traits in Wheat.

Grain nitrogen (N) uptake (GNup) in winter wheat (Triticum aestivum L.) is influenced by multiple components at the plant organ level and by pre- and post-flowering N uptake (Nup). Although spectral proximal high-throughput sensing is promising for field phenotyping, it was rarely evaluated for such N traits. Hence, 48 spectral vegetation indices (SVIs) were evaluated on 10 measurement days for the estimation of 34 N traits in four data subsets, representing the variation generated by six high-yielding cultivars, two N fertilization levels (N), two sowing dates (SD), and two fungicide (F) intensities. Close linear relationships (p < 0.001) were found for GNup both in response to cultivar differences (Cv; R2 = 0.52) and other agronomic treatments (R2 = 0.67 for Cv*F*N, R2 = 0.53 for Cv*SD*N and R2 = 0.57 for the combined treatments), notably during milk ripeness. Especially near-infrared (NIR)/red edge SVIs, such as the NDRE_770_750, outperformed NIR/visible light (VIS) indices. Index rankings and seasonal R2 values were similar for total Nup, while the N harvest index, which expresses the partitioning to the grain, was moderately estimated only during dough ripeness, primarily from indices detecting contrasting senescence between different fungicide intensities. Senescence-sensitive indices, including R787_R765 and TRCARI_OSAVI, performed best for N translocation efficiency and some organ-level N traits at maturity. Even though grain N concentration was best assessed by the red edge inflection point (REIP), the blue/green index (BGI) was more suited for leaf-level N traits at anthesis. When SVIs were quantitatively ranked by data subsets, a better agreement was found for GNup, total Nup, and grain N concentration than for several contributing N traits. The results suggest (i) a good general potential for estimating GNup and total Nup by (ii) red edge indices best used (iii) during milk and early dough ripeness. The estimation of contributing N traits differs according to the agronomic treatment.

Genetic variation and intraspecific diversity for agro-morphological and nutritional traits in African yam bean

ABSTRACTGenetic variability and intraspecific diversity in African yam bean (AYB) [Sphenostylis stenocarpa (Hochst ex A. Rich) Harms] germplasm can be exploited for developing improved cultivars. Our objective was to determine variability and diversity in AYB relative to agro-morphological and seed nutritional composition-related traits. We evaluated 30 African yam bean genotypes for two cropping years. Highly significant (P < 0.01) variation was detected for the genotypes and year effects for all the investigated traits, indicating the diversity of the genotypes and dissimilarity of the two cropping years in the study. The significant genotype-by-year interactions for all the investigated traits indicate that single-year testing is not sufficient to identify genotypes with consistent performance across years. Heritability estimates were relatively high for seed nutritional traits as well as for yield, suggesting the likely effectiveness of selection. There was a weak genotypic correlation between seed yield and seed phytic acid content, suggesting that the two traits are not controlled by the same genes. The genotypes were differentiated into six agro-nutritional groups, from which crosses between divergent groups would provide a wide spectrum of variability in segregating generations to ensure the efficiency of selection for superior genotypes. TSs 363 containing low phytic acid with high seed yield, Fe, Zn and protein contents was identified in this study, and this, in combination with other promising genotypes, should be further explored for breeding nutritionally improved, high-yielding cultivars.

State analysis and global trends in the cultivation of european olives

Aim. To analyze the scientific and technical literature, to identify trends and prospects for world production of olives. Discussion. Olive is one of the most cultivated fruit crops in the world. It surpasses the main fruit crops in the area of cultivation: apple, pear, peach and nectarine, apricot and orange, and is second only to coffee. In the period from 1994 to 2017 a significant tendency of increasing this value from 7.66 to 10.8 million hectares was noted. In addition, world fruit production is steadily growing from 11.47 million tons (in 1994) to 20.87 million tons (in 2017). The main producing regions of this crop are Europe (67% of world production), Africa (15.4%), Asia (15.3%). South and North America (2.1%) and Oceania (0.2%) make a minor contribution to the global production of olives. The leading countries-producers of olives are Spain, Italy, Greece, Turkey, Morocco, Tunisia, Syria, Egypt, Portugal and Algeria. The most efficient production of olives was observed in the USA and Egypt (11.97 and 11.45 t / ha, respectively), which is associated with the use of highly productive orchards of the intensive type and the cultivation of modern cultivars of olives. Main conclusions. In recent years, there has been a significant increase in the area of cultivation, gross yield, yield of olive. Despite the fact that Europe maintains a leading position in the production of olive fruit, according to FAO, there is a significant increase in production in Africa and Asia. Different efficiency of cultivation of olives is noted by countries, which justifies the use of highly productive orchards of intensive type with high planting density, as well as the use of modern high-yielding cultivars.

Identification of quantitative trait loci for panicle structure and grain filling using a cross between indica- and japonica-type high-yielding rice cultivars

ABSTRACTTo enhance the yield potential of rice by breeding, it is important to reveal the genetic factors affecting yield components in high-yielding cultivars. Quantitative trait loci (QTL) analysis for panicle structure and spikelet weight as an index of grain filling was conducted using recombinant inbred lines (RILs) derived from a cross between an indica-dominant high-yielding cultivar, Takanari, and a japonica-dominant high-yielding cultivar, Momiroman in 2012 and 2013 in eastern Japan. The grain-filling ability of Takanari is reported to be better than that of Momiroman. Since grain filling is generally better near the tip of the panicle and decreases as the number of branches from the rachis increases, we classified whole panicles into upper and lower side panicles and spikelets into primary, secondary, and tertiary spikelets according to the number of branches from the rachis. On chromosomes 1, 4, and 6, QTLs regulating the number of spikelets per panicle and panicle structure were detected and were most likely identical to GN1a, SPIKE, and APO1, respectively, which has been previously reported as QTLs regulating the number of spikelets per panicle. Takanari produced much heavier secondary and tertiary spikelets than Momiroman on the lower side panicle. On chromosome 5, novel QTLs regulating spikelet weight were detected. The Takanari allele enhanced secondary and tertiary spikelet weight on the lower side panicle. These results indicate that it may be possible to enhance sink capacity and translocation of source with a combination of novel QTLs detected on chromosome 5 and GN1, APO1, and SPIKE.

Water-conserving and biomass-allocation traits are associated with higher yields in modern cultivars compared to landraces of soybean [Glycine max (L.) Merr.] in rainfed water-limited environments

Drought is one of the main factors restricting the productivity of soybean (Glycine max L.), especially in arid and semi-arid areas where the crop may suffer from frequent and severe drought events unless irrigated. The aim of the present study was to determine the plant responses to water deficits in four landraces and four modern soybean cultivars that differed in yield in rainfed water-limited environments to determine the characteristics associated with yield under drought in the field and under a rainout shelter. During a slow progressive soil drying cycle, the stomata began to close at higher soil water contents (SWC) of 65–67% vs 61–63%, photosynthesis began to decrease at higher SWC of 60–62% vs 52–54% and leaf hydraulic conductance fell by 20% at higher SWC of 50–67% vs 36–48%, while the leaf relative water content began to decrease at lower SWC of 30–35% vs 38–39% in modern cultivars than landraces, respectively, indicating that the modern cultivars exhibited greater isohydric behaviour than the landraces. Water use after flowering was lower in the modern cultivars, consistent with the conservative leaf physiology, but yield was not correlated or negatively correlated with water use so the higher yield and water use efficiency for grain in the modern cultivars was associated with lower water use and higher distribution of biomass to grain, i.e., a higher harvest index. We conclude that breeders of modern high-yielding cultivars of soybean for rainfed semiarid environments have selected for lower biomass and leaf area, larger grain size and higher harvest index, while also selecting for stronger isohydric behaviour and water-conserving traits.

Recent advances and perspectives in crop biofortification

The increasing world population and limited amount of land area appropriate for intensive agriculture necessitate high-yield cultivars. The focus is on the enrichment of existing crops deficient in nutrients, which is also called biofortification. Microelements, vitamins, and fatty acids belong to most important traits being subjected to biofortification. Biofortification strategies can be divided on fertilization-based strategy, which is characterized by direct application of nutrients or plant growth promoting substances on plants, and biotechnological strategy, which involves molecular biology techniques in order to enhance transport, production, and accumulation of nutrients. Recent advances in plant biotechnology, such as genome-editing, clustered regularly interspaced short palindromic repeats (CRISPR)-associated 9, and transcription activator-like effector nuclease, as well as an extensive study of genetic diversity, are acceptable approaches to the development of biofortified crops.

Effect of cellulase and Lactobacillus casei on ensiling characteristics, chemical composition, antioxidant activity, and digestibility of mulberry leaf silage

With the lack of feed resources in China, mulberry leaves have been developed as a ruminant forage rich in protein and functional components. To make full use of mulberry leaves, including their nutrients and biological activities, we investigated the effects of cellulase and Lactobacillus casei LC on the nutritive value and antioxidant capacity of mulberry leaf silage. Mulberry leaves from 2 locally prevailing high-yield cultivars were separately subjected to ensiling treatments either with or without addition of Lactobacillus culture, in combination with variable levels of cellulase application. After 60-d ensiling, the resulting silage was sampled and analyzed for fermentation parameters, antioxidant activity, carbohydrates, and protein fractions, as well as in vitro rumen gas production. The results showed that nutrients, including functional components of mulberry leaves, were well preserved during the ensiling process. Compared with the control, the application of cellulase and Lactobacillus casei LC resulted in greater dry matter recovery, higher contents of lactic acid, true protein, and total flavonoid, and increased antioxidant activity and microbial protein production, as well as decreased pH value, lower concentrations of ammonium nitrogen, and lower fiber fractions in the mulberry leaf silage, which varied between the 2 selected mulberry cultivars. These results suggest that mulberry leaf silage could be a quality feed with robust antioxidant capacity, which could be improved by the application of cellulase and Lactobacillus casei LC.

Root plasticity and Pi recycling within plants contribute to low-P tolerance in Tibetan wild barley

BackgroundBarley is a low phosphorus (P) demand cereal crop. Tibetan wild barley, as a progenitor of cultivated barley, has revealed outstanding ability of tolerance to low-P stress. However, the underlying mechanisms of low-P adaption and the relevant genetic controlling are still unclear.ResultsWe identified low-P tolerant barley lines in a doubled-haploid (DH) population derived from an elite Tibetan wild barley accession and a high-yield cultivar. The tolerant lines revealed greater root plasticity in the terms of lateral root length, compared to low-P sensitive lines, in response to low-P stress. By integrating the QTLs associated with root length and root transcriptomic profiling, candidate genes encoding isoflavone reductase, nitrate reductase, nitrate transporter and transcriptional factor MYB were identified. The differentially expressed genes (DEGs) involved the growth of lateral root, Pi transport within cells as well as from roots to shoots contributed to the differences between low-P tolerant line L138 and low-P sensitive lines L73 in their ability of P acquisition and utilization.ConclusionsThe plasticity of root system is an important trait for barley to tolerate low-P stress. The low-P tolerance in the elite DH line derived from a cross of Tibetan wild barley and cultivated barley is characterized by enhanced growth of lateral root and Pi recycling within plants under low-P stress.

Identifying key traits in high-yielding rice cultivars for adaptability to both temperate and tropical environments

Increasing rice yield potential is a continuous challenge posed by world population growth. To increase yield potential, favorable alleles of valuable genes need to be accumulated in promising germplasm. We conducted comparative yield trials for two years in Tsukuba, Japan, in a temperate region and at the International Rice Research Institute (IRRI), Philippines, in a tropical region using five high-yielding rice cultivars: Takanari and Hokuriku193, developed in Japan, and IR64, NSIC Rc158, and YTH183, developed in the Philippines. Genotype plus genotype × environment interaction (GGE) biplot analysis across four environments (two regions × two seasons) classified the five cultivars into four categories: Takanari and YTH183 showed high adaptability to both tropical and temperate regions, Hokuriku193 was suitable for temperate regions, NSIC Rc158 was suitable for the tropics, and IR64 was inferior to the other cultivars in both regions. The high yield and adaptability in Takanari and YTH183 were attributed to their large sink capacity with good grain filling. The plant type for high yield was different, however, between the two cultivars; Takanari was a panicle-weight type, whereas YTH183 was a panicle-number type. Evaluations of F2 progeny of a cross between Takanari and YTH183 showed transgressive segregation for number of panicles per plant as well as number of spikelets per panicle, leading some F2 plants to produce more spikelets per plant (corresponding to larger sink size) than the parental cultivars in both regions. These results suggest the possibility of developing rice cultivars with high yield potential in both temperate and tropical regions by crossing temperate with tropical high-yielding cultivars.

Variability of performance and its structural elements in spring barley cultivars

The aim and tasks of the study. Mutual influence of performance elements and the strength of this influence to predict the effectiveness of selections for performance in spring barley breeding were studied, and the least varying performance traits were identified.Material and methods. The study was conducted in variety testing experiments with a plot area of 10 m2 in 2015–2018. Thirty typical plants were harvested for structural analysis. The significance of differences was assessed by analysis of variance in a Microsoft Excel spreadsheet. Six varieties selected out of 25 accessions, because they were the most highly productive and adapted, were taken as the test material.Correlation analysis was performed, and the variation coefficients were computed, as BA Dospekhov described [22] using the Microsoft Excel spreadsheet and STATISTICA 10 software; their significance levels were assessed with the STATISTICA 10 software.Results and discussion. We found that in this sample of cultivars the spike length (V = 1.46–5.18%) was the least varying, depending on the growing conditions, and the grain weight per spike (V = 11.8–45.7%) and performance (V = 8.50–43.90%) were the most varying. There was only a close linear relationship between the performance and the grain number in the main spike; the productive tillering did not always determine the performance, as it depended on the weather conditions. In terms of variability degree, we established that in this sample of cultivars Avhur was the most plastic and responded to changes in the growing conditions, and Khors and Ahrarii showed stable performance.Changes in the direction and strength of correlations between the performance elements depended on the growing conditions. Under the influence of specific conditions, the contributions of structural elements to the performance redistributed, that is, a compensatory effect was observed.Conclusions. The expression variability of the performance elements and their correlations depended on the growing conditions; therefore, many years of research are needed to establish patterns. For this sample of high-yielding cultivars, the productive tillering is not always a determinant of the performance; selecting high-yielding accessions, one should focus on the grain number per spike. Cultivar Avhur can be recommended for breeding as a source of high performance, and cultivars Khors and Ahrarii - as sources of stable performance.

Integrated sugarcane farming and sugar milling with selective fermentation: A simulation-based approach

Abstract Selective fermentation of reducing sugars in cane juice harnesses the advantageous productivity of high-yielding sugarcane cultivars for increasing products from limited arable land. Without this technology, the altered compositions of cane juice often lead to additional environmental impacts due to increased consumption of externally supplied energy and compensated yield of sugar. In this paper, the effects of coordinated transition of sugarcane farming and sugar milling on the yield of final products, energy consumption, operability in the crystallization process, and economic feasibility were analyzed in simulation across various sugarcane cultivars. An integrated sugarcane farming and sugar milling process model (SugaNol) was extended from a previous work to consistently balance mass and energy considering the characteristics of the selective fermentation technology. A case study demonstrated that the coordinated introduction of selective fermentation with the high-yielding cultivar enhanced sugar production by 8.5% and ethanol production by 17.9%, improved operability in the crystallization process, and lead to a cleaner production by achieving above without consuming additional fossil fuels, although the market price of ethanol should be under 95 JPY L −1 for profitability. Furthermore, the specific characteristics of cultivars to make selective fermentation economically feasible are presented as a guideline for future cultivar development.

High mesophyll conductance in the high-yielding rice cultivar Takanari quantified with the combined gas exchange and chlorophyll fluorescence measurements under free-air CO2 enrichment

ABSTRACTAn effective strategy for increasing crop production is increasing the rate of photosynthesis. In this study, we conducted gas exchange and chlorophyll fluorescence measurements for a high-yielding rice cultivar, Takanari, to identify the leaf physiological properties that contribute to high capacity for photosynthesis of the uppermost leaves before (panicle initiation stage) and after heading (grain-filling stage) in the Tsukuba free-air CO2 enrichment (FACE) facility. The higher photosynthesis rate of Takanari compared with that of the commonly cultivated cultivar, Koshihikari, was mainly attributed to the greater stomatal conductance for CO2 (gsc) at the panicle initiation stage and to the greater mesophyll conductance (gm) at the grain-filling stage in both current and elevated atmospheric CO2 concentrations [CO2]. Takanari had a higher level of leaf nitrogen content (Nl) compared with Koshihikari at the grain-filling stage, which led to greater gm and maximum carboxylation rate (Vc,max), but Nl alone did not explain the variations of gm within the variety. A clear correlation was found between Vc,max and Nl. Calculating Vc,max taking gm into consideration removed the artifact of Vc,max25 in relation to Nl that was observed when gm was assumed to be infinite. Our results emphasize the need to separate the roles of Vc,max and gm to accurately understand the ecophysiological processes that control leaf photosynthesis in Takanari.

Variability and correlations of economically valuable traits in cowpea from the VIR collection in the environments of Astrakhan provincer

Background. The problem of a deficit in vegetable protein and the need to diversify agricultural produce require involvement of new and little-known crops, such as cowpea, in the production. Cowpea (Vigna unguiculata (L.) Walp.) is a high-protein leguminous crop; its breeding and production have been intensified in Russia only in recent years. The study of the VIR collection, carried out at the Institute’s branch in Astrakhan, makes it possible to disclose the crop’s breeding potential. Objective: Studying the range of variability and tracing the relationships of economically valuable traits in vegetable (green pod) cowpea under the conditions of Astrakhan Province.Materials and methods. In 2008‑2010, a study was implemented at an experiment plot of the Astrakhan branch of VIR. Thirty- three accessions of green pod cowpea from the VIR collection were studied to analyze the variability of 12 phenotypic traits. Positive and negative correlations were identified between the following characters: interphase periods (flowering, industrial ripeness and seed maturation), shape of the shrub, lengths of the stem and to the first pod, length and weight of the pod, number of seeds per pod, presence of a parchment layer and fiber in pod valves, pod yield per plant, number of pods and peduncles, seed weight per plant, and weight of 1000 seeds.Results and conclusion. Medium variability was observed for such characters as the interphase periods ‘shoots–industrial ripeness’ and ‘shoots– seed maturation’, number of seeds per pod, and weight of 1000 seeds: the coefficient of variation (CV) was 15‑18%. High variation was registered for the length and weight of the pod (CV = 26‑32%), shrub shape, stem length, and length of the stem up to the first pod (CV = 35‑37%). The widest ranges of variability were demonstrated in the quantitative yield characters of cowpea accessions: number of pods per plant (CV = 33‑49%), number of flower stalks (CV = 38‑51%), and seed weight per plant (CV = 38‑44%), which means that cowpea yield is quite susceptible to weather conditions. During the three years of studying, the lowest levels of variability in economically valuable traits were characteristic of the accessions of the early-ripening group: k‑668 and k‑873 (China); mid- ripening group: k‑971 (India); and late-ripening group: k‑141 (China). Cowpea pod productivity depended to the greatest degree from mean values of the number of pods per plant (r = 0,73) and the number of peduncles (r = 0,71). The identified correlations in the productivity components make it possible to optimize the selection of accessions promising as source materials for the development of new high-yielding cultivars.

Multi-Trait Diverse Germplasm Sources from Mini Core Collection for Sorghum Improvement

Sorghum is a multipurpose crop cultivated in over 100 countries, but its productivity is constrained by several biotic and abiotic stresses. Therefore, sorghum improvement programs largely focus on developing high-yielding cultivars with multiple traits including stress resistance, bioenergy and nutritional quality. This study was undertaken to meet breeders’ needs to develop such cultivars and identify diverse germplasm sources with multiple traits. The 242 sorghum mini core accessions were evaluated for agronomic traits (yield, maturity, 100-seed weight) in two post-rainy seasons under optimally irrigated and drought conditions and identified 21 accessions as a sources for agronomic traits. The evaluation of mini core revealed 70 accessions resistant to biotic stress, 12 to abiotic stress, 13 for bioenergy traits and 27 for nutritional traits. The 13,390 single nucleotide polymorphism markers on mini core were used to identify genetically diverse accessions with desirable agronomic traits: IS 23684 (nutrition traits, diseases, insect pests), IS 1212 (earliness, nutrition traits, drought, seedling vigor, diseases), IS 5094 (yield, drought, diseases, insect pests), IS 473 (earliness, diseases), IS 4698 (yield, Brix %, insect pests) and IS 23891 (greater seed weight, yield, Brix %, drought, diseases). These are useful genetic resources that meet breeders needs to develop agronomically superior sorghum cultivars with desirable combinations of multiple traits and a broad genetic base.

4R Management of Phosphorus Fertilizer in the Northern Great Plains.

Phosphorus (P) fertilizer has played a vital role in increasing the productivity of crop production in the northern Great Plains for approximately 100 years. Throughout this period, agricultural production practices have changed dramatically, while our knowledge of P behavior and beneficial management practices has improved. Some of the more recent and substantial changes in farming practices on the northern Great Plains include widespread adoption of reduced tillage systems, introduction of new crops and high-yielding cultivars, intensification and extension of crop rotations, development of new fertilizer products, increased appreciation of the role of microbial interactions in P dynamics, and growing concern for the effects of P on water quality. As cropping systems, technology, and societal demands evolve over time, nutrient management practices must also evolve to address concerns and take advantage of emerging opportunities. Classic principles and new P fertilizer technologies and management practices must be integrated into packages of 4R practices that optimize crop yield and agronomic efficiency while minimizing negative environmental impact and conserving P resources. Although a wide range of products and practices can be combined for this approach, placing ammonium phosphate fertilizer in a band, in or near the seed-row, at the time of seeding and at a rate that matches P removal by the crop generally provides the greatest P efficiency, long-term sustainability, and environmental protection for small grain, oilseed, and pulse crop production in the northern Great Plains.

Statistical analysis of phenotypic traits of rice (Oryza sativa L.) related to grain yield under neck blast disease

Investigating the traits of rice in conditions of blast disease and its relationship with grain yield can help to identify suitable strategies for selecting high-yielding cultivars, especially in areas prevalent with the disease. One hundred and twenty-one rice cultivars and lines (genotypes) selected from the collection of the Rice Research Institute of Iran were evaluated for the traits related to neck blast disease, including number of filled and unfilled grains per panicle, neck blast infection type, 1000-grain weight, number of productive panicles per plant, and grain yield. Mean square of genotypes was highly significant (P < 0.01) for all traits, and most of the traits exhibited a high heritability with low level of phenotypic variations in each genotype, indicating the small environmental effect in this study. Grain yield in infected plants correlated significantly with number of filled and unfilled grains per panicle and with 1000-grain weight. Through a multiple regression analysis, three traits including number of filled grains per panicle, number of productive panicles per plant and 1000-grain weight were entered to the model in a stepwise method, which justified 86% of grain yield variances in infected plants. Also direct and indirect effects of each trait were evaluated by path analysis. Three main and independent factors identified with factor analysis explained 72.86% of the changes in the all data. The cluster analysis for classification of genotypes according the traits revealed six main clusters, in which five genotypes were identified as resistant genotypes. The results of principle component analysis also confirmed the results of cluster analysis.

Salt Tolerance Improvement in Rice through Efficient SNP Marker-Assisted Selection Coupled with Speed-Breeding

Salinity critically limits rice metabolism, growth, and productivity worldwide. Improvement of the salt resistance of locally grown high-yielding cultivars is a slow process. The objective of this study was to develop a new salt-tolerant rice germplasm using speed-breeding. Here, we precisely introgressed the hst1 gene, transferring salinity tolerance from “Kaijin” into high-yielding “Yukinko-mai” (WT) rice through single nucleotide polymorphism (SNP) marker-assisted selection. Using a biotron speed-breeding technique, we developed a BC3F3 population, named “YNU31-2-4”, in six generations and 17 months. High-resolution genotyping by whole-genome sequencing revealed that the BC3F2 genome had 93.5% similarity to the WT and fixed only 2.7% of donor parent alleles. Functional annotation of BC3F2 variants along with field assessment data indicated that “YNU31-2-4” plants carrying the hst1 gene had similar agronomic traits to the WT under normal growth condition. “YNU31-2-4” seedlings subjected to salt stress (125 mM NaCl) had a significantly higher survival rate and increased shoot and root biomasses than the WT. At the tissue level, quantitative and electron probe microanalyzer studies indicated that “YNU31-2-4” seedlings avoided Na+ accumulation in shoots under salt stress. The “YNU31-2-4” plants showed an improved phenotype with significantly higher net CO2 assimilation and lower yield decline than WT under salt stress at the reproductive stage. “YNU31-2-4” is a potential candidate for a new rice cultivar that is highly tolerant to salt stress at the seedling and reproductive stages, and which might maintain yields under a changing global climate.

Breeding Biofortified Pearl Millet Varieties and Hybrids to Enhance Millet Markets for Human Nutrition

Pearl millet is an important food crop in the arid and semi-arid tropical regions of Africa and Asia. Iron and zinc deficiencies are widespread and serious public health problems worldwide, including in India and Africa. Biofortification is a cost-effective and sustainable agricultural strategy to address this problem. The aim of this review is to provide the current biofortification breeding status and future directions of the pearl millet for growing nutrition markets. Research on the pearl millet has shown that a large genetic variability (30–140 mg kg−1 Fe and 20–90 mg kg−1 Zn) available in this crop can be effectively utilized to develop high-yielding cultivars with high iron and zinc densities. Open-pollinated varieties (Dhanashakti) and hybrids (ICMH 1202, ICMH 1203 and ICMH 1301) of pearl millet with a high grain yield and high levels of iron (70–75 mg kg−1) and zinc (35–40 mg kg−1) densities have been developed and released first in India. Currently, India is growing &gt; 70,000 ha of biofortified pearl millet, and furthermore more pipeline cultivars are under various stages of testing at the national (India) and international (west Africa) trials for a possible release. Until today, no special markets existed to promote biofortified varieties and hybrids as no incentive price to products existed to address food and nutritional insecurity simultaneously. The market demand is likely to increase only after an investment in crop breeding and the integration into the public distribution system, nutritional intervention schemes, private seed and food companies with strong mainstreaming nutritional policies. The following sections describe various aspects of breeding and market opportunity for addressing micronutrient malnutrition.

Growth, yield formation, and inulin performance of a non-food energy crop, Jerusalem artichoke (Helianthus tuberosus L.), in a semi-arid area of China

Jerusalem artichoke is an important crop that is used as a foodstuff, animal feed, and an energy crop. However, there has been little fundamental research on its breeding, and a lack of elite cultivars has seriously limited its industrial use. This study was conducted to characterize Jerusalem artichoke’s yield formation mechanism based on its growth and photosynthetic characteristics, to identify reliable criteria for high yield cultivar screening, and to guide the breeding of new high yield cultivars. High yield group (MH) cultivars exhibited vigorous aboveground and root growth, higher photosynthetic capacities (especially in terms of their ability to utilize weak light and minimize dark respiration) and lower rates of sexual reproduction than low yield group (ML) cultivars. Traits associated strongly with high yields included a high leaf area index (LAI), plant height, and stem diameter; a low dark respiration rate (Rd), light compensation point (LCP), and light saturation point (LSP); and late maturation with a long vegetative period. In addition, high yields were due more to increases in tuber number than tuber size, and growth under elevated CO2 conditions was identified as a potentially effective way of increasing yields. The tubers of high yield cultivars exhibited elevated inulin contents, and the inulin content depended more on the total sugar content than the reducing sugar content. Because high yield cultivars have low rates of sexual reproduction, it may be necessary to complement hybrid breeding efforts with mutation breeding, molecular breeding, and other breeding strategies to improve Jerusalem artichoke yields.