Thousand-kernel Weight Research Articles

Unlocking the relationships among population structure, plant architecture, growing season, and environmental adaptation in Henan wheat cultivars

BackgroundEcological environments shape plant architecture and alter the growing season, which provides the basis for wheat genetic improvement. Therefore, understanding the genetic basis of grain yield and yield-related traits in specific ecological environments is important.ResultsA structured panel of 96 elite wheat cultivars grown in the High-yield zone of Henan province in China was genotyped using an Illumina iSelect 90 K SNP assay. Selection pressure derived from ecological environments of mountain front and plain region provided the initial impetus for population divergence. This determined the dominant traits in two subpopulations (spike number and spike percentage were dominance in subpopulation 2:1; thousand-kernel weight, grain filling rate (GFR), maturity date (MD), and fertility period (FP) were dominance in subpopulation 2:2), which was also consistent with their inheritance from the donor parents. Genome wide association studies identified 107 significant SNPs for 12 yield-related traits and 10 regions were pleiotropic to multiple traits. Especially, GY was co-located with MD/FP, GFR and HD at QTL-ple5A, QTL-ple7A.1 and QTL-ple7B.1 region. Further selective sweep analysis revealled that regions under selection were around QTLs for these traits. Especially, grain yield (GY) is positively correlated with MD/FP and they were co-located at the VRN-1A locus. Besides, a selective sweep signal was detected at VRN-1B locus which was only significance to MD/FP.ConclusionsThe results indicated that extensive differential in allele frequency driven by ecological selection has shaped plant architecture and growing season during yield improvement. The QTLs for yield and yield components detected in this study probably be selectively applied in molecular breeding.

Starch Metabolism in Wheat: Gene Variation and Association Analysis Reveal Additive Effects on Kernel Weight.

Kernel weight is a key determinant of yield in wheat (Triticum aestivum L.). Starch consists of amylose and amylopectin and is the major constituent of mature grain. Therefore, starch metabolism in the endosperm during grain filling can influence kernel weight. In this study, we sequenced 87 genes involved in starch metabolism from 300 wheat accessions and detected 8,141 polymorphic sites. We also characterized yield-related traits across different years in these accessions. Although the starch contents fluctuated, thousand kernel weight (TKW) showed little variation. Polymorphisms in six genes were significantly associated with TKW. These genes were located on chromosomes 2A, 2B, 4A, and 7A; none were associated with starch content or amylose content. Variations of 15 genes on chromosomes 1A and 7A formed haplotype blocks in 26 accessions. Notably, accessions with higher TKWs had more of the favorable haplotypes. We thus conclude that these haplotypes contribute additive effects to TKW.

Comparison of energy of planting methods in wheat production in a semi-arid region

ABSTRACT For sustainable agriculture, efficient use of energy is of utmost importance. This study was conducted for a period of 3 years in Central Anatolia region of Turkey to find out how the energy balance was affected under different planting methods. Split plot design with four replications was used in the study. While the main plots included planting methods, the subplots included the varieties. Energy use efficiency, energy productivity, specific energy and net energy were investigated. According to the results obtained, energy inputs were found to be lower in bed planting (26.38 GJ ha−1), when compared with conventional flat planting (26.51 GJ ha−1). Energy use efficiency was found to be higher in conventional flat planting (7.15) when compared with bed planting (5.39). While grain yield (GY), biomass yield (BY) and number of spikes m2 (NS) were found to be higher with conventional flat planting, harvest index (HI) and thousand kernel weight (TKW) were found to be higher with bed planting. It was concluded that the variety chosen was extremely important in the success of bed planting method.

Impact of elevated CO2 on two contrasting wheat genotypes exposed to intermediate drought stress at anthesis

AbstractThe objective of this experiment was to investigate the responses of contrasting wheat genotypes to drought stress under ambient and elevated CO2 environments. At anthesis, the plants from each CO2 levels were either exposed to progressive drought or well‐watered at 95% of pot holding capacity. The results showed that for both genotypes, CO2 elevation sensitized the plants’ response to soil drying in terms of reduction of evapotranspiration. Drought significantly reduced trans‐zeatin (tZ) concentration in leaves, salicylic acid (SA) concentration in spikes, and physiological and yield‐related traits. However, the concentration of abscisic acid (ABA) and other phytohormones was increased under drought, which coincided with an increase in the kernel abortion. Elevated CO2 significantly increased photosynthetic rate, but had no significant effect on yield‐related traits. Genotype L3 possessed higher concentration of leaf tz, osmotic potential, and spike SA/ABA ratio under combined drought and elevated CO2 as compared to genotype L2. L3 also had higher thousand kernel weight (TKW) and grain yield in comparison to L2. The results indicate that elevated CO2 is not necessarily increasing yield, and biophysiochemical traits in L3 could be used as valuable selecting criteria to obtain higher TKW and grain yield in future drier and CO2‐enriched environment.

ЕФЕКТИВНІСТЬ ГУМІНОВИХ СТИМУЛЯТОРІВ ЗА УМОВИ ПЕРЕДПОСІВНОЇ ОБРОБКИ НАСІННЯ ЗЕРНОВИХ КУЛЬТУР

Гумінові речовини є важливим елементом технології вирощування польових культур, застосовую-чи які можна впливати на ріст і розвиток рослин фактично на всіх етапах органогенезу. Метою до-сліджень було виявити ефективність протруйників, гумінових стимуляторів на процеси проростан-ня насіння, формування ознак продуктивності ячменю ярого і пшениці озимої та перспективи їхньо-го використання у виробництві. У ході проведення досліджень використано такі наукові методи: аналіз, синтез, польовий, статистичний. Статистично встановлений характер взаємозв’язків оз-нак, які вивчали в експерименті, свідчить, що головними параметрами формування продуктивності пшениці озимої є маса зерна з рослини та продуктивне кущіння, а для ячменю ярого – маса 1000 зе-рен. Проте урожайність зернових культур визначається значно складнішою системою, оскільки елементи структури продуктивності культур, зокрема маса 1000 зерен, маса зерна з рослини та кількість продуктивних пагонів прямо впливають на урожайність (r=0,34–0,71), а вона своєю чер-гою залежать від маси корінців проростка. Розраховано, що між масою корінців проростка і кількі-стю продуктивних стебел кореляція є прямою із середнім ступенем зв’язку ( r=0,54), а між масою корінців проростка і масою зерна з рослини кореляційний зв’язок сильний (r=0,85). За результатами досліджень встановлено, що застосування гуматів позитивно впливало на наростання надземної маси ячменю ярого. За умови обробки насіння пшениці озимої відзначено істотний закономірний вплив цього елементу технології на біометричні параметри рослин, однак суттєву роль відігравали і сортові властивості культури. Застосування гумінових препаратів для передпосівної обробки насін-ня UB for seeds і 1R Seed treatment призвело до зростання маси проростка на 8–19,6 %, а на пшениці – в межах 11–16 %. Потенційна врожайність зросла відповідно на 8,8–12,7 та 28,3 % відповідно.

ВПЛИВ СОРТОВИХ ОСОБЛИВОСТЕЙ НА ЯКІСТЬ ЗЕРНА ПШЕНИЦІ ОЗИМОЇ

У статті доведено актуальність вирощування якісної озимої пшениці в Україні як головної про-довольчої культури та цінної в польовій сівозміні. Мета дослідження полягає в оцінюванні фізичних і хімічних властивостей сортів пшениці озимої для того, щоб для виявити кращі характеристики для подальшого призначення використання зерна. Зерно пшениці озимої сортів Оржиця, Полтавчанка, Царичанка, Зелений гай, Кармелюк, Аріївка, Лютенька, Сагайдак, Диканька (селекція Полтавської державної аграрної академії) для проведення досліджень вирощувалось на полях НВП із селекції та насінництва. Лабораторні дослідження якості зерна пшениці озимої проведено в сертифікованій Держспоживстандартом України лабораторії Полтавської державної аграрної академії. Фізичні та хімічні показники якості зерна пшениці озимої було визначено відповідно до загальноприйнятих методик, які відповідають ГОСТу або ДСТУ. Дослідження показало високу енергію проростання усіх сортів озимої пшениці, а найвищий показник схожості спостерігався у сортів Зелений гай (96 %) і Царичанка (94 %). Найменший показник у сорту Оржиця – 86 %, що теж свідчить про гарну схо-жість. Визначення впливу сортових властивостей на масу 1000 зерен показало найвищий показник у сорту Зелений гай (48,0 г), а найменший – у сорту Оржиця (39,7 г). Оцінка наведених зразків на скло-подібність виявила найвищий показник у сорту Зелений гай (97 %), а найменший – у сорту Полтав-чанка (70 %). Проаналізувавши отримані результати досліджень, можна зробити висновок, що ці сорти є кращими для випічки хлібобулочних виробів. Аналіз впливу сортових властивостей на хіміч-ний склад зерна пшениці озимої проводився за показниками: вміст клейковини, число падіння, вміст білка, число седиментації. Виявлено, що найбільший вміст клейковини має сорт Лютенька (37 %), найменші – сорти Оржиця (30 %), Диканька (31 %) та Зелений гай (31 %). Визначення деформації клейковини показало, що у досліджуваних сортах пшениці переважає друга група і показники коли-ваються від 88 до 102 одиниць. Результати дослідження числа падіння показали, що зерна пшениці озимої мають показники від 206 с (що є прийнятним) до 452 с (що є збільшеним показником, тому кінцева якість хлібобулочних виробів може бути не найкращою). Проведення досліджень вмісту біл-ка засвідчило, що всі 9 сортів пшениці озимої відповідають визнаним стандартам. Найнижчий пока-зник вмісту білка має сорт Оржиця (13,6 %), а найвищий – сорт Лютенька (16,9 %). Оцінка числа седиментації показала, що більшість із представлених зразків належать до високих – понад 50 мл і більше. Лише один зразок зерна пшениці озимої Аріївка має середній показник у 34 мл. Отже, ми ви-ділили два сорти – Зелений гай і Лютенька, які показали найкращі результати за всіма параметрами і показниками. Відмічена позитивна динаміка у показниках майже всіх сортів, що доводить їх спро-можність давати стабільні сходи та стійкість до несприятливих умов.

Inter-Relationships between Test Weight, Thousand Kernel Weight, Kernel Size Distribution and Their Effects on Durum Wheat Milling, Semolina Composition and Pasta Processing Quality.

Although most of the durum wheat produced in the Canadian prairies in 2017 and 2018 met the test weight (TW) requirements for the top grades of Canada Western Amber Durum (CWAD), some samples of top grades were inferior in milling quality. To understand the abnormality, this study was conducted to investigate TW, thousand kernel weight (TKW) and kernel size distribution (KSD) in relation to durum milling potential, semolina composition and pasta quality. With reduction of kernel size, semolina and total milling yields decreased progressively, and kernels passing through no.6 slotted sieve had detrimental impact on milling. The overall relationship between TW and milling yields appeared to be genotype dependent. At similar TW, variety showed lower milling yields had greater proportion of smaller kernels. By account for the difference in KSD, greater relationships (R2 > 0.91, p < 0.001) were found for TKW and proportion of kernels passing No.6 slotted sieve with milling yields than TW (R2 = 0.75, p < 0.001). This infers potential use of small kernels (passing No.6 slotted sieve) as a new objective grading factor for rapid prediction of milling quality of CWAD. Although small kernels exhibited much higher yellow pigment than the larger ones, pasta made from small kernels was duller, redder and less yellow, likely due to the higher semolina ash and protein contents, which adversely affected pasta color.

Incredible Role of Osmotic Adjustment in Grain Yield Sustainability under Water Scarcity Conditions in Wheat (Triticum aestivum L.).

Interrogations of local germplasm and landraces can offer a foundation and genetic basis for drought tolerance in wheat. Potential of drought tolerance in a panel of 30 wheat genotypes including varieties, local landraces, and wild crosses were explored under drought stress (DS) and well-watered (WW) conditions. Considerable variation for an osmotic adjustment (OA) and yield components, coupled with genotype and environment interaction was observed, which indicates the differential potential of wheat genotypes under both conditions. Reduction in yield per plant (YP), thousand kernel weight (TKW), and induction of OA was detected. Correlation analysis revealed a strong positive association of YP with directly contributing yield components under both environments, indicating the impotence of these traits as a selection-criteria for the screening of drought-tolerant genotypes for drylands worldwide. Subsequently, the association of OA with TKW which contributes directly to YP, indicates that wheat attains OA to extract more water from the soil under low water-potential. Genotypes including WC-4, WC-8 and LLR-29 showed more TKW under both conditions, among them; LLR-29 also has maximum OA and batter yield comparatively. Result provides insight into the role of OA in plant yield sustainability under DS. In this study, we figure out the concept of OA and its incredible role in sustainable plant yield in wheat.

Activities of leaf and spike carbohydrate-metabolic and antioxidant enzymes are linked with yield performance in three spring wheat genotypes grown under well-watered and drought conditions

BackgroundTo improve our understanding about the physiological mechanism of grain yield reduction at anthesis, three spring wheat genotypes [L1 (advanced line), L2 (Vorobey) and L3 (Punjab-11)] having contrasting yield potential under drought in field were investigated under controlled greenhouse conditions, drought stress was imposed at anthesis stage by withholding irrigation until all plant available water was depleted, while well-watered control plants were kept at 95% pot water holding capacity.ResultsCompared to genotype L1 and L2, pronounced decrease in grain number (NGS), grain yield (GY) and harvest index (HI) were found in genotype L3, mainly due to its greater kernel abortion (KA) under drought. A significant positive correlation of leaf monodehydroascorbate reductase (MDHAR) with both NGS and HI was observed. In contrast, significant negative correlations of glutathione S-transferase (GST) and vacuolar invertase (vacInv) both within source and sink were found with NGS and HI. Likewise, a significant negative correlation of leaf abscisic acid (ABA) with NGS was noticed. Moreover, leaf aldolase and cell wall peroxidase (cwPOX) activities were significantly and positively associated with thousand kernel weight (TKW).ConclusionDistinct physiological markers correlating with yield traits and higher activity of leaf aldolase and cwPOX may be chosen as predictive biomarkers for higher TKW. Also, higher activity of MDHAR within the leaf can be selected as a predictive biomarker for higher NGS in wheat under drought. Whereas, lower activity of vacInv and GST both within leaf and spike can be selected as biomarkers for higher NGS and HI. The results highlighted the role of antioxidant and carbohydrate-metabolic enzymes in the modulation of source-sink balance in wheat crops, which could be used as bio-signatures for breeding and selection of drought-resilient wheat genotypes for a future drier climate.

Yerel Yulaf (Avena sativa L.) Genotiplerinin Eskişehir Koşullarında Tane Verimi ve Bazı Kalite Özellikleri

Geçit Kuşağı Tarımsal Araştırma Enstitüsü Müdürlüğü (GKTAEM)‘ndeki yulaf ıslah çalışmaları 1929 yılından beri sürdürülmektedir. Bu çalışma kapsamında, bölge koşullarına uyumlu yerel yulaf hatlarından verimi ve kalitesi yüksek olanların seçilerek, yeni çeşit olarak tescil ettirilmesi hedeflenmiştir. Denemeler, 2017-2018 üretim yılında Eskişehir GKTAEM Merkez ve Hamidiye yerleşkelerinde yağmura bağımlı koşullarda yürütülmüş olup, bu çalışmada, ülkenin değişik yerlerinden toplanan 19 yerel hat ile standart olarak Checota, Kahraman, Kırklar, Yeniçeri ve Sebat çeşitleri kullanılmıştır. Bu araştırmada genotiplerde tane verimi (TV), bin tane ağırlığı (BTA), bitki boyu (BB), yatma değeri (YD), salkım çıkarma süresi (SÇS) gibi çeşitli agro-morfolojik özelliklerinin yanı sıra tane protein oranı (TPO) ve beta glukan oranı (BG), asit deterjan lif (ADF) ve nötral deterjan lif (NDF) değerleri incelenmiştir. Elde edilen bulgulara göre, ADF ve NDF değerleri dışındaki parametrelerde genotipler arası farklılıklar istatistiksel olarak önemli bulunmuş olup, TV (2,31 – 3,58 t ha-1) değerleri arasında ortalama olarak 2,93 t ha-1 hesaplanmış; genotiplerdeki BTA (25,5 – 37,1 g) arasında bulunmuş; BB ise (83,3 – 130,2 cm) olarak belirlenmiş; YD (%1 – 57) şeklinde notlanmış; SÇS (126,0 – 141,0 gün) şeklinde saptanmış; BG (%3,29 – 5,16) arasında değişmiş; TPO (%13,4 – 15,9) arasında olmuş; ADF ve NDF oranları sırayla, (%16,4 – 19,4) ile (%30,8 – 38,8) arasında belirlenmiştir. Buna göre, G13, G16, G19, G21, G22 ve G23 yerel yulaf hatlarının hedeflenen agro-morfolojik ve kalite özellikleri bakımından yeterli oldukları anlaşılarak ilgili ıslah programında bir üst kademeye aktarılması sağlanmıştır.

Genome-wide association mapping reveals putative candidate genes for drought tolerance in barley

Drought is one of the most important abiotic stresses limiting yield production in cereal crops which deleteriously affects food security worldwide. The study aimed to identify marker-trait associations (MTAs) and putative candidate genes underlying agronomic and seed related traits under post-anthesis drought stress in a set of 183 spring barley gene bank accessions from 23 countries that were genotyped with a 9 K SNP chip. Plants were grown in the field in two consecutive years and post-anthesis drought stress was simulated by spraying 1% KI ten days after anthesis. The treatment caused a significant reduction in total biomass by 10.7 %, in kernel number by 2.5 %, in kernel weight per spike by 21.4 % and in thousand kernel weight (TKW) by 16.7 %, whereby most tolerant accessions were HOR 5970, HOR 6606 and HOR 6560. GWAS analysis of best linear unbiased estimators (BLUEs) revealed 97 significant MTAs associated with kernel number and kernel weight per spike and confirmed prominent regions such as 2H (18.9 cM), 6H (54.8 cM) and 7H (70.5-71.0 cM) for drought response and were co-localized with ten putative candidate genes. Gene annotation indicates that genes for the plant respiratory burst oxidase homologs (rboh) family, the carotenoid cleavage dioxygenase 1 (CCD1) and RNA-binding proteins (RBPs) might be involved in tolerance and stress response mechanisms during post-anthesis drought stress. In conclusion, the study provides essential information about significant MTAs and candidate genes related to drought tolerance which can be further used for marker-assisted selection. More drought tolerant barley accessions may be used as pre-bred material to widen the genetic diversity of cultivated barley and to meet the demands for cultivars in world’s areas which suffer post-anthesis drought stress.

The NAC transcription factor NAC019-A1 is a negative regulator of starch synthesis in wheat developing endosperm.

Starch is a major component of wheat (Triticum aestivum L.) endosperm and is an important part of the human diet. The functions of many starch synthesis genes have been elucidated. However, little is known about their regulatory mechanisms in wheat. Here, we identified a novel NAC transcription factor, TaNAC019-A1 (TraesCS3A02G077900), that negatively regulates starch synthesis in wheat and rice (Oryza sativa L.) endosperms. TaNAC019-A1 was highly expressed in the endosperm of developing grains and encoded a nucleus-localized transcriptional repressor. Overexpression of TaNAC019-A1 in rice and wheat led to significantly reduced starch content, kernel weight, and kernel width. The TaNAC019-A1-overexpression wheat lines had smaller A-type starch granules and fewer B-type starch granules than wild-type. Moreover, TaNAC019-A1 could directly bind to the 'ACGCAG' motif in the promoter regions of ADP-glucose pyrophosphorylase small subunit 1 (TaAGPS1-A1, TraesCS7A02G287400) and TaAGPS1-B1 (TraesCS7B02G183300) and repress their expression, thereby inhibiting starch synthesis in wheat endosperm. One haplotype of TaNAC019-B1 (TaNAC019-B1-Hap2, TraesCS3B02G092800) was positively associated with thousand-kernel weight and underwent positive selection during the Chinese wheat breeding process. Our data demonstrate that TaNAC019-A1 is a negative regulator of starch synthesis in wheat endosperm and provide novel insight into wheat yield improvement.

AAC Redstar hard red spring wheat

AAC Redstar is an early maturing, high-yielding hard red spring wheat (Triticum aestivum L.) cultivar that is well adapted to the northern Canadian Prairies and eligible for grades of Canada Western Red Spring (CWRS) wheat. Over 3 yr (2016–2018) of testing in the Parkland Wheat Cooperative registration trials, AAC Redstar was 11% higher yielding than AC Splendor, 6% higher than Parata, and 4% higher than Glenn and Carberry. AAC Redstar matured 3 d earlier than Glenn, 2 d earlier than Carberry, and had similar maturity to Parata. AAC Redstar was shorter than all checks except Carberry and had better lodging resistance compared with all the check cultivars in the registration trial. The test weight and thousand-kernel weight of AAC Redstar were similar to Carberry. The grain protein concentration of AAC Redstar was 0.2% lower than Carberry. AAC Redstar was rated moderately resistant to Fusarium head blight, leaf rust, stripe rust, and common bunt. AAC Redstar had resistant reactions to loose smut and stem rust. AAC Redstar was registered under the CWRS market class.

Agronomic performance of durum wheat landraces and modern cultivars and its association with genotypic variation in vernalization response (Vrn-1) and photoperiod sensitivity (Ppd-1) genes

This study analyzed the relationship between important agronomic traits and major genes regulating flowering time in a panel of 151 Mediterranean durum wheat landraces and 20 modern cultivars. Field experiments were conducted under rainfed conditions during six crop seasons in northeastern Spain. Multivariate analysis of agronomic traits and genotypic data allowed the modern cultivars to be differentiated from the landraces and germplasm pools to be identified within the landraces associated with their geographic origin. The high frequency of the Vrn-A1c allele and the photoperiod insensitive alleles GS105 and GS100 at Ppd-A1 reduced time to anthesis and enlarged the grain filling period of the modern cultivars compared with the landraces. Ancient durums collected close to the domestication area of wheat showed a high frequency of the winter allele vrn-B1 and the photoperiod sensitivity allele Ppd-B1b. None of the allele variants or allelic combinations accounted significantly for variations in any agronomic trait of modern cultivars. Vernalization and photoperiod genes acted additively in explaining the genotypic variance for the agronomic traits of the landraces. Vrn-A1 alleles and Vrn-A1+Vrn-B1 allelic combinations significantly affected the number of grains per spike (NGS), thousand kernel weight (TKW) and grain filling rate (R), accounting for 9%?12% of the genotypic variance for these traits. Ppd-1 accounted for 6%?21% of the genotypic variance for R, grain filling duration (GFD), plant height (PH), biomass at anthesis (CDW) and harvest index (HI). Vrn-1+Ppd-1 allelic combinations accounted for 21%?26% of the genotypic variance for these traits. Except for NGS, the effect of vernalization and photoperiod genes on the agronomic traits was linked to their effect on anthesis time. The three-day delay in anthesis time caused by the allele Vrn-A1d irrespective of the allele Vrn-A1c resulted in increases of 10 % in R and 7% in TKW. The eight-day delay in anthesis time caused by the allele Ppd-A1(DelCD) compared with Ppd-A1(GS105) increased R by 19 % and PH by 28 %, but reduced GFD and HI by 10 %. None of the allele variants or allelic combinations at the Vrn-1 or Ppd-1 genes accounted significantly for variations in yield or number of spikes m?2 (NSm2).

Relationships between grain physicochemical characteristics and flour particle size distribution for Taiwan rice cultivars

Fourteen cultivars of rice, 5 indica, 6 japonica and 3 waxy types were used to investigate the relationship between grain physicochemical characteristics and particle size distributions of rice flour. The data showed that particle size index (PSI) negatively correlated with the resistance time (RT) and milling temperature of Stenvert hardness test, damaged starch of rice flour, and percentage retained on 60 mesh (> 60 mesh %) (p < 0.05), but positively correlated with percentage that passed through 60 mesh and retained on 100 mesh (60-100 mesh %) (p < 0.05). From principal component analysis (PCA), the first and the second principal components, describing 56.14 and 21.44% of the variance of rice samples, respectively. The first principal component highly correlated with variables including RT, > 60 mesh %, milling temperature of Stenvert hardness test and damaged starch of rice flour, but negatively correlated with hardness index of Brabender micro-hardness test (BMHT), 60-100 mesh % and PSI. The second principal component positively correlated with ash and fat contents, but negatively correlated with shape and thousand-kernel weight (TKW) of rice grains. The effect of protein content was intermediate between the first and second principal component. Based on the results of PCA, the rice grain physical characteristics (i.e., RT and BMHT) are major factors, followed by chemical compositions, affecting the rice flour particle size distributions.

Genomic prediction of yield and root development in wheat under changing water availability

BackgroundDeeper roots help plants take up available resources in deep soil ensuring better growth and higher yields under conditions of drought. A large-scale semi-field root phenotyping facility was developed to allow a water availability gradient and detect potential interaction of genotype by water availability gradient. Genotyped winter wheat lines were grown as rows in four beds of this facility, where indirect genetic effects from neighbors could be important to trait variation. The objective was to explore the possibility of genomic prediction for grain-related traits and deep root traits collected via images taken in a minirhizotron tube under each row of winter wheat measured.ResultsThe analysis comprised four grain-related traits: grain yield, thousand-kernel weight, protein concentration, and total nitrogen content measured on each half row that were harvested separately. Two root traits, total root length between 1.2 and 2 m depth and root length in four intervals on each tube were also analyzed. Two sets of models with or without the effects of neighbors from both sides of each row were applied. No interaction between genotypes and changing water availability were detected for any trait. Estimated genomic heritabilities ranged from 0.263 to 0.680 for grain-related traits and from 0.030 to 0.055 for root traits. The coefficients of genetic variation were similar for grain-related and root traits. The prediction accuracy of breeding values ranged from 0.440 to 0.598 for grain-related traits and from 0.264 to 0.334 for root traits. Including neighbor effects in the model generally increased the estimated genomic heritabilities and accuracy of predicted breeding values for grain yield and nitrogen content.ConclusionsSimilar relative amounts of additive genetic variance were found for both yield traits and root traits but no interaction between genotypes and water availability were detected. It is possible to obtain accurate genomic prediction of breeding values for grain-related traits and reasonably accurate predicted breeding values for deep root traits using records from the semi-field facility. Including neighbor effects increased the estimated additive genetic variance of grain-related traits and accuracy of predicting breeding values. High prediction accuracy can be obtained although heritability is low.

Genome-wide association analysis of stem water-soluble carbohydrate content in bread wheat.

GWAS identified 36 potentially new loci for wheat stem water-soluble carbohydrate (WSC) contents and 13 pleiotropic loci affecting WSC and thousand-kernel weight. Five KASP markers were developed and validated. Water-soluble carbohydrates (WSC) reserved in stems contribute significantly to grain yield (GY) in wheat. However, knowledge of the genetic architecture underlying stem WSC content (SWSCC) is limited. In the present study, 166 diverse wheat accessions from the Yellow and Huai Valleys Winter Wheat Zone of China and five other countries were grown in four well-watered environments. SWSCC at 10 days post-anthesis (10DPA), 20DPA and 30DPA, referred as WSC10, WSC20 and WSC30, respectively, and thousand-kernel weight (TKW) were assessed. Correlation analysis showed that TKW was significantly and positively correlated with WSC10 and WSC20. Genome-wide association study was performed on SWSCC and TKW with 373,106 markers from the wheat 660K and 90K SNP arrays. Totally, 62 stable loci were detected for SWSCC, with 36, 24 and 19 loci for WSC10, WSC20 and WSC30, respectively; among these, 36 are potentially new, 16 affected SWSCC at two or three time-points, and 13 showed pleiotropic effects on both SWSCC and TKW. Linear regression showed clear cumulative effects of favorable alleles for increasing SWSCC and TKW. Genetic gain analyses indicated that pyramiding favorable alleles of SWSCC had simultaneously improved TKW. Kompetitive allele-specific PCR markers for five pleiotropic loci associated with both SWSCC and TKW were developed and validated. This study provided a genome-wide landscape of the genetic architecture of SWSCC, gave a perspective for understanding the relationship between WSC and GY and explored the theoretical basis for co-improvement of WSC and GY. It also provided valuable loci and markers for future breeding.

Wheat Flour Milling Yield Estimation Based on Wheat Kernel Physical Properties Using Artificial Neural Networks

Wheat is a stable food raw material for the majority of people around the world as wheat-based products provide an important part of the daily energy intake in many countries. Wheat is generally milled into flour prior to use in the bakery industry. Flour yield is one of the major quality criteria in wheat milling. Flout yield detection requires large amount of sample, costly machinery, longer time of tempering and milling practices requiring substantial workload. In this study, artificial neural network (ANN) approach has been employed to predict flour milling yield. The ANN was designed in the MATLAB software using such wheat physical properties as hectoliter weight, thousand-kernel weight, kernel size distribution, and grain hardness. Flour yields and four different kernel physical features (hectoliter weight, thousand-kernel weight, kernel size distribution, and grain hardness) were first collected from 2400 wheat samples through the conventional methods. The ANN was trained using 85% of 2400 flour yield data and tested with 15% of the remaining data. In the training of the ANN, various models have been investigated to find the best ANN structure. Additionally, two data sets with and without grain hardness have been employed to determine the effect of grain hardness on the prediction performance of the ANN model. It was found that grain hardness which reduced the MAE values from 2.3333 to 2.2611 and RMSE values from 3.0775 to 2.9146 gave better result. The results proved that the developed ANN model can be used to estimate flour yield using wheat kernel physical properties.

Coordination of carbon and nitrogen accumulation and translocation of winter wheat plant to improve grain yield and processing quality

The objective of this work was to characterize the accumulation of carbon (C) and nitrogen (N), and the translocation of wheat (Triticum aestivum L.) cultivars to achieve both high-quality and high-yield. Twenty-four wheat cultivars, including 12 cultivars containing high-quality gluten subunit 5 + 10 at Glu-D1, and 12 cultivars with no Glu-D1 5 + 10, were planted at Yuanyang and Xuchang in Henan Province, during 2016–2017, and 2017–2018 cropping seasons. Wheat cultivars containing Glu-D1 5 + 10 had an advantage in grain quality traits. Significant difference (P < 0.05) was observed for grain protein concentration (GPC) between 5 + 10 group and no 5 + 10 group. Grain yield (GY) was significantly correlated with kernel number (KN) (r = 0.778, P < 0.01), thousand-kernel weight (TKW) (r = 0.559, P < 0.01), dry matter accumulation at post-anthesis (r = 0.443, P < 0.05), and stem water-soluble carbohydrate (WSC) accumulation (r = 0.487, P < 0.05) and translocation amount (r = 0.490, P < 0.05). GPC, dough stability time (DST) and nitrogen agronomic efficiency (NAE) were significantly correlated with nitrogen accumulation (NAA) at maturity stage (r = 0.524, = 0.404, = 0.418, P < 0.01, < 0.05, < 0.05, respectively), and nitrogen translocation amount (r = 0.512, = 0.471, = 0.405, P < 0.05, < 0.05, < 0.05, respectively). These results suggest that good-quality, high-yield, and high-efficiency could achieve through the selection of high-quality wheat cultivars and coordination of C and N accumulation and translocation. High-quality gluten subunit gene Glu-D1 5 + 10 and stem WSC could be used as a selection index for breeding and production of high-quality and high-yield wheat.

Development of an Evaluation System for Fusarium Resistance in Wheat Grains and Its Application in Assessment of the Corresponding Effects of Fhb1.

Fusarium head blight (FHB) caused by Fusarium species is a globally important wheat disease. Host resistance to FHB is composed of multiple mechanisms, including resistance to initial infection (type I), disease spread (type II), toxin accumulation (type III), kernel infection (type IV), and yield loss (type V), of which the last three have been less studied. Traditionally, the Fusarium-damaged kernel rate (FDK; percentage of Fusarium-infected grains) from point- or spray-inoculated experiments was used as the parameter for type IV resistance, which may be problematic because of the influence of type II resistance. Here we propose a new definition for type IV resistance: that is, the resistance against Fusarium infection expressed in wheat grains that have the same chance in contact with the pathogen, under favorable temperature and humidity for infection. Fhb1 confers strong type II resistance, leading to significantly reduced FHB severity and FDK. To investigate the role of Fhb1 in type IV resistance, a pair of near-isogenic lines, R22W (Fhb1 carrier, resistant in terms of type II resistance) and S22V (non-Fhb1, susceptible), along with eight wheat genotypes differing at Fhb1 were inoculated at different grain development stages with Fusarium macrospores both in vivo and in vitro. The in vivo experiments with all florets inoculated demonstrated a significant reduction in thousand kernel weight (TKW) in inoculated grains, regardless of their Fhb1 status and developmental stages. Surprisingly, R22W showed more TKW reduction than S22V, which was supported by the scanning electron microscopy observation that confirmed the more severe degradation of starch granules in R22W grains. The in vitro experiments demonstrated that grains from both R22W and S22V promoted fungal colonization, but no significant difference was found between the two lines. In summary, our results indicated that the proposed type IV evaluation system is effective in determining different grain resistance levels, providing novel tools for FHB resistance breeding. The finding that Fhb1 is not associated with type IV resistance enriches our understanding of this gene.