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Spike length (SL) is one of the most important agronomic traits affecting yield potential and stability in wheat. In this study, a major stable quantitative trait locus (QTL) for SL, i.e., qSl-2B, was detected in multiple environments in a recombinant inbred line (RIL) mapping population, KJ-RILs, derived from a cross between Kenong 9204 (KN9204) and Jing 411 (J411). The qSl-2B QTL was mapped to the 60.06–73.06 Mb region on chromosome 2B and could be identified in multiple mapping populations. An InDel molecular marker in the target region was developed based on a sequence analysis of the two parents. To further clarify the breeding use potential of qSl-2B, we analyzed its genetic effects and breeding selection effect using both the KJ-RIL population and a natural mapping population, which consisted of 316 breeding varieties/advanced lines. The results showed that the qSl-2B alleles from KN9204 showed inconsistent genetic effects on SL in the two mapping populations. Moreover, in the KJ-RILs population, the additive effects analysis of qSl-2B showed that additive effect was higher when both qSl-2D and qSl-5A harbor negative alleles under LN and HN. In China, a moderate selection utilization rate for qSl-2B was found in the Huanghuai winter wheat area and the selective utilization rate for qSl-2B continues to increase. The above findings provided a foundation for the genetic improvement of wheat SL in the future via molecular breeding strategies. Key message: A major stable QTL for spike length was identified in wheat, and its genetic effect on yield related-traits as well as its potential use value in molecular breeding programs were characterized. [ABSTRACT FROM AUTHOR]

Context. Plant height and spike length are important traits with significant impact on the potential yield of wheat. It is essential to dissect their genetic control in order to improve yield potential through breeding. Aims. We aimed to identify genomic regions with stable and major-effect quantitative trail loci (QTLs) associated with plant height and spike length in common wheat (Triticum aestivum L.). Methods. Three recombinant inbred line (RIL) mapping populations were created by crossing a common parental line, Roshan, with three different cultivars: Sabalan, Falat, and Superhead. The RILs were grown over 3 years at five locations under water-stressed and well-watered conditions. Plant height and spike length were measured during each experiment, and inclusive composite interval mapping was used to analyse the data in both single-and multi-environment analyses. Key results. Single-environment analysis detected 32 additive QTLs in the three populations. Three novel, stable and non-epistatic QTLs were identified: qPH1D for plant height in the Sabalan background; and qSL1D and qSL1B.3 for spike length in the Falat and Superhead backgrounds, respectively. Between the flanking markers on chromosomes 1B, 1D and 4B, 191 genes were predicted, 20 of which were identified as potential candidates with roles in wheat plant height and spike-related traits. Conclusions. The study identified stable QTLs for plant height and spike length in wheat, providing valuable markers for future breeding programs and enhancing yield potential. Implications. These results lay a good foundation for fine mapping of QTLs/genes for molecular marker-assisted breeding in wheat in the future. [ABSTRACT FROM AUTHOR]

Spike length (SL) plays an important role in the yield improvement of wheat and is significantly associated with other traits. Here, we used a recombinant inbred line (RIL) population derived from a cross between Yangmai 12 (YM12) and Yanzhan 1 (YZ1) to construct a genetic linkage map and identify quantitative trait loci (QTL) for SL. A total of 5 QTL were identified for SL, among which QSl.yaas-3A and QSl.yaas-5B are two novel QTL for SL. The YZ1 alleles at QSl.yaas-2D and QSl.yaas-5A, and the YM12 alleles at QSl.yaas-2A, QSl.yaas-3A, and QSl.yaas-5B conferred increasing SL effects. Two major QTL QSl.yaas-5A and QSl.yaas-5B explained 9.11–15.85% and 9.01–12.85% of the phenotypic variations, respectively. Moreover, the positive alleles of QSl.yaas-5A and QSl.yaas-5B could significantly increase Fusarium head blight (FHB) resistance (soil surface inoculation and spray inoculation were used) and thousand-grain weight (TGW) in the RIL population. Kompetitive allele-specific PCR (KASP) markers for QSl.yaas-5A and QSl.yaas-5B were developed and validated in an additional panel of 180 wheat cultivars/lines. The cultivars/lines harboring both the positive alleles of QSl.yaas-5A and QSl.yaas-5B accounted for only 28.33% of the validation populations and had the longest SL, best FHB resistance (using spray inoculation), and highest TGW. A total of 358 and 200 high-confidence annotated genes in QSl.yaas-5A and QSl.yaas-5B were identified, respectively. Some of the genes in these two regions were involved in cell development, disease resistance, and so on. The results of this study will provide a basis for directional breeding of longer SL, higher TGW, and better FHB resistance varieties and a solid foundation for fine-mapping QSl.yaas-5A and QSl.yaas-5B in future. [ABSTRACT FROM AUTHOR]

Summary: Plant breeding is constrained by trade‐offs among different agronomic traits by the pleiotropic nature of many genes. Genes that contribute to two or more favourable traits with no penalty on yield are rarely reported, especially in wheat. Here, we describe the editing of a wheat auxin response factor TaARF12 by using CRISPR/Cas9 that rendered shorter plant height with larger spikes. Changes in plant architecture enhanced grain number per spike up to 14.7% with significantly higher thousand‐grain weight and up to 11.1% of yield increase under field trials. Weighted Gene Co‐Expression Network Analysis (WGCNA) of spatial–temporal transcriptome profiles revealed two hub genes: RhtL1, a DELLA domain‐free Rht‐1 paralog, which was up‐regulated in peduncle, and TaNGR5, an organ size regulator that was up‐regulated in rachis, in taarf12 plants. The up‐regulation of RhtL1 in peduncle suggested the repression of GA signalling, whereas up‐regulation of TaNGR5 in spike may promote GA response, a working model supported by differential expression patterns of GA biogenesis genes in the two tissues. Thus, TaARF12 complemented plant height reduction with larger spikes that gave higher grain yield. Manipulation of TaARF12 may represent a new strategy in trait pyramiding for yield improvement in wheat. [ABSTRACT FROM AUTHOR]

E3 ubiquitin ligase genes play important roles in the regulation of plant development. They have been well studied in plants, but have not been sufficiently investigated in wheat. Here, we identified a highly expressed RING finger E3 ubiquitin ligase gene TaAIRP2-1B (ABA-insensitive RING protein 2) in wheat spike. Sequence polymorphism and association analysis showed that TaAIRP2 - 1B is significantly associated with spike length under various conditions. The genotype with haplotype Hap -1B-1 of TaAIRP2 - 1B has a longer spike than that of Hap -1B-2, and was positively selected in the process of wheat breeding in China. Moreover, the TaAIRP2-1B -overexpressing rice lines have longer panicles compared with wild-type plants. The expression levels of TaAIRP2-1B in Hap -1B-1 accessions were higher than in Hap -1B-2 accessions. Further study revealed that the expression of TaAIRP2-1B was negatively regulated by TaERF3 (ethylene-responsive factor 3) via binding to the Hap -1B-2 promoter, but not via binding of Hap -1B-1. Additionally, several candidate genes interacting with TaAIRP2-1B were obtained by screening the cDNA library of wheat in yeast cells. It was found that TaAIRP2-1B interacted with TaHIPP3 (heavy metal-associated isoprenylated protein 3) and promoted TaHIPP3 degradation. Our study demonstrates that TaAIRP2-1B controls spike length, and the haplotype Hap -1B-1 of TaAIRP2 - 1B is a favorable natural variation for spike length enhancement in wheat. This work also provides genetic resources and functional markers for wheat molecular breeding. [ABSTRACT FROM AUTHOR]

Spikelet number and grain number per spike are two crucial and correlated traits for grain yield in wheat. Photoperiod-1 (Ppd-1) is a key regulator of inflorescence architecture and spikelet formation in wheat. In this study, near-isogenic lines derived from the cross of a synthetic hexaploid wheat and commercial cultivars generated by double top-cross and two-phase selection were evaluated for the number of days to heading and other agronomic traits. The results showed that heading time segregation was conferred by a single incomplete dominant gene PPD-D1, and the 2 kb insertion in the promoter region was responsible for the delay in heading. Meanwhile, slightly delayed heading plants and later heading plants obviously have advantages in grain number and spikelet number of the main spike compared with early heading plants. Utilization of PPD-D1 photoperiod sensitivity phenotype as a potential means to increase wheat yield potential. [ABSTRACT FROM AUTHOR]

In order to clarify the effect of propionyl brassinolide on rice plant traits and yield, the single factor Latin square design was used in the experiment. The test factor was 0. 003% propionyl brassinolide aqueous solution application concentration. Four treatments were set up, treatment A (500 times dilution), treatment B (2 000 times dilution), treatment C (3 000 times dilution), treatment D (4 000 times dilution), and spraying the same amount of water blank control (CK). Each treatment was repeated five times. Before harvest,plant related traits and yield components were investigated, and yield was measured separately for each repetition. The results showed that after rice transplanting, propionyl brassinolide diluted 2 000 times liquid was sprayed twice on the leaf surface, the plant height was 100. 9 cm, the number of tillers was 23. 0, the length of the lower panicle internode, the second internode from the top and the third internode from the bottom were 22. 3, 19. 7 and 16. 4 cm respectively, the total number of grains per panicle, the number of filled grains and the weight of 1 000 grains were 137. 2 grains, 128. 9 grains and 32. 1 g, respectively, and the yield was 7 362. 7 kg/ hm² . Therefore, 0. 003% propionyl brassinolide aqueous solution diluted 2 000 times can increase plant height, internode length, tiller number and yield of rice. [ABSTRACT FROM AUTHOR]

Keywords: RING finger E3 ubiquitin ligase; spike length; TaAIRP2-1B EN RING finger E3 ubiquitin ligase spike length TaAIRP2-1B 4889 4891 3 09/15/23 20230913 NES 230913 Spike architecture involves many key yield-related agronomic traits in crops. The ubiquitin-proteasome system regulates the stability of substrate proteins and consists of three enzymes: ubiquitin-activating enzyme E1, ubiquitin-conjugating enzyme E2, and ubiquitin ligase E3. RING finger E3 ubiquitin ligase gene TaAIRP2-1B controls spike length in wheat. [Extracted from the article]

Background: Plant height (PH), spike length (SL) and spike compactness (SCN) are important agronomic traits in wheat due to their strong correlations with lodging and yield. Thus, dissection of their genetic basis is essential for the improvement of plant architecture and yield potential in wheat breeding. The objective of this study was to map quantitative trait loci (QTL) for PH, SL and SCN in a recombinant inbred line (RIL) population derived from the cross 'PuBing3228 × Gao8901' (PG-RIL) and to evaluate the potential values of these QTL to improve yield. Results: In the current study, Five, six and ten stable QTL for PH, SL, and SCN, respectively, were identified in at least two individual environments. Five major QTL QPh.cas-5A.3, QPh.cas-6A, QSl.cas-6B.2, QScn.cas-2B.2 and QScn.cas-6B explained 5.58–25.68% of the phenotypic variation. Notably, two, three and three novel stable QTL for PH, SL and SCN were identified in this study, which could provide further insights into the genetic factors that shape PH and spike morphology in wheat. Conditional QTL analysis revealed that QTL for SCN were mainly affected by SL. Moreover, a Kompetitive Allele Specific PCR (KASP) marker tightly linked to stable major QTL QPh.cas-5A.3 was developed and verified using the PG-RIL population and a natural population. Conclusions: Twenty-one stable QTL related to PH, SL, and SCN were identified. These stable QTL and the user-friendly marker KASP8750 will facilitate future studies involving positional cloning and marker-assisted selection in breeding. [ABSTRACT FROM AUTHOR]

Background: Plant height (PH), spike length (SL) and spike compactness (SCN) are important agronomic traits in wheat due to their strong correlations with lodging and yield. Thus, dissection of their genetic basis is essential for the improvement of plant architecture and yield potential in wheat breeding. The objective of this study was to map quantitative trait loci (QTL) for PH, SL and SCN in a recombinant inbred line (RIL) population derived from the cross 'PuBing3228 × Gao8901' (PG-RIL) and to evaluate the potential values of these QTL to improve yield. Results: In the current study, Five, six and ten stable QTL for PH, SL, and SCN, respectively, were identified in at least two individual environments. Five major QTL QPh.cas-5A.3, QPh.cas-6A, QSl.cas-6B.2, QScn.cas-2B.2 and QScn.cas-6B explained 5.58–25.68% of the phenotypic variation. Notably, two, three and three novel stable QTL for PH, SL and SCN were identified in this study, which could provide further insights into the genetic factors that shape PH and spike morphology in wheat. Conditional QTL analysis revealed that QTL for SCN were mainly affected by SL. Moreover, a Kompetitive Allele Specific PCR (KASP) marker tightly linked to stable major QTL QPh.cas-5A.3 was developed and verified using the PG-RIL population and a natural population. Conclusions: Twenty-one stable QTL related to PH, SL, and SCN were identified. These stable QTL and the user-friendly marker KASP8750 will facilitate future studies involving positional cloning and marker-assisted selection in breeding. [ABSTRACT FROM AUTHOR]

Wheat grain yield is affected by plant height, which is the total length of spike, the uppermost internode, and other elongated internodes. In this study, a population of recombinant inbred lines generated from a cross between two advanced winter wheat breeding lines were phenotyped over four locations/years and genotyped by using markers of genotyping-by-sequencing (GBS) and Diversity Array Technology (DArT) for mapping of genes for three traits, including spike length, the uppermost internode length, and plant height. Five genomic regions or quantitative trait loci (QTLs) were associated with candidate genes for these traits. A major QTL was associated with Q5A, and two novel haplotypes of Q5A were identified, one for a single nucleotide polymorphism (SNP) at position -2,149 in promoter region and the other for copy number variation. Compared with one copy Q5A on chromosome 5A in Chinese Spring, the novel haplotype of Q5A with two copies Q5A was found to generate spikes that are extremely compacted. A major QTL was associated with allelic variation in the recessive vrn-A1 alleles involving in protein sequences, and this QTL was associated with increased uppermost internode length but not with plant height. A major QTL for plant height was associated with Rht-B1b on chromosome 4B, but its effects could be compromised by two new minor QTLs on chromosome 7. Collectively, the favorable alleles from the four loci can be used to establish the optimal plant height in wheat. [ABSTRACT FROM AUTHOR]

Background: Wheat (Triticum aestivum L.) is an important cereal crop. Increasing grain yield for wheat is always a priority. Due to the complex genome of hexaploid wheat with 21 chromosomes, it is difficult to identify underlying genes by traditional genetic approach. The combination of genetics and omics analysis has displayed the powerful capability to identify candidate genes for major quantitative trait loci (QTLs), but such studies have rarely been carried out in wheat. In this study, candidate genes related to yield were predicted by a combined use of linkage mapping and weighted gene co-expression network analysis (WGCNA) in a recombinant inbred line population. Results: QTL mapping was performed for plant height (PH), spike length (SL) and seed traits. A total of 68 QTLs were identified for them, among which, 12 QTLs were stably identified across different environments. Using RNA sequencing, we scanned the 99,168 genes expression patterns of the whole spike for the recombinant inbred line population. By the combined use of QTL mapping and WGCNA, 29, 47, 20, 26, 54, 46 and 22 candidate genes were predicted for PH, SL, kernel length (KL), kernel width, thousand kernel weight, seed dormancy, and seed vigor, respectively. Candidate genes for different traits had distinct preferences. The known PH regulation genes Rht-B and Rht-D, and the known seed dormancy regulation genes TaMFT can be selected as candidate gene. Moreover, further experiment revealed that there was a SL regulatory QTL located in an interval of about 7 Mbp on chromosome 7A, named TaSL1, which also involved in the regulation of KL. Conclusions: A combination of QTL mapping and WGCNA was applied to predicted wheat candidate genes for PH, SL and seed traits. This strategy will facilitate the identification of candidate genes for related QTLs in wheat. In addition, the QTL TaSL1 that had multi-effect regulation of KL and SL was identified, which can be used for wheat improvement. These results provided valuable molecular marker and gene information for fine mapping and cloning of the yield-related trait loci in the future. [ABSTRACT FROM AUTHOR]

Diversity surveys of germplasm are important for gaining insight into the genomic basis for crop improvement; especially InDels, which are poorly understood in hexaploid common wheat. Here, we describe a map of 89,923 InDels from exome sequencing of 262 accessions of a Chinese wheat mini-core collection. Population structure analysis, principal component analysis and selective sweep analysis between landraces and cultivars were performed. Further genome-wide association study (GWAS) identified five QTL (Quantitative Trait Loci) that were associated with spike length, two of them, on chromosomes 2B and 6A, were detected in 10 phenotypic data sets. Assisted with RNA-seq data, we identified 14 and 21 genes, respectively that expressed in spike and rachis within the two QTL regions that can be further investigated for candidate genes discovery. Moreover, InDels were found to be associated with awn length on chromosomes 5A, 6B and 4A, which overlapped with previously reported genetic loci B1 (Tipped 1), B2 (Tipped 2) and Hd (Hooded). One of the genes TaAGL6 that was previously shown to affect floral organ development was found at the B2 locus to affect awn length development. Our study shows that trait-associated InDels may contribute to wheat improvement and may be valuable molecular markers for future wheat breeding [ABSTRACT FROM AUTHOR]

Background: Kernel number per spike (KNS) and spike length (SL) are important spike-related traits in wheat variety improvement. Discovering genetic loci controlling these traits is necessary to elucidate the genetic basis of wheat yield traits and is very important for marker-assisted selection breeding. Results: In the present study, we used a recombinant inbred line population with 248 lines derived from the two founder genotypes of wheat, Bima4 and BainongAK58, to construct a high-density genetic map using wheat 55 K genotyping assay. The final genetic linkage map consists of 2356 bin markers (14,812 SNPs) representing all 21 wheat chromosomes, and the entire map spanned 4141.24 cM. A total of 7 and 18 QTLs were identified for KNS and SL, respectively, and they were distributed on 11 chromosomes. The allele effects of the flanking markers for 12 stable QTLs, including four QTLs for KNS and eight QTLs for SL, were estimated based on phenotyping data collected from 15 environments in a diverse wheat panel including 384 elite cultivars and breeding lines. The positive alleles at seven loci, namely, QKns.his-7D2–1, QKns.his-7D2–2, QSl.his-4A-1, QSl.his-5D1, QSl.his-4D2–2, QSl.his-5B and QSl.his-5A-2, significantly increased KNS or SL in the diverse panel, suggesting they are more universal in their effects and are valuable for gene pyramiding in breeding programs. The transmission of Bima4 allele indicated that the favorite alleles at five loci (QKns.his-7D2–1, QSl.his-5A-2, QSl.his-2D1–1, QSl.his-3A-2 and QSl.his-3B) showed a relatively high frequency or an upward trend following the continuity of generations, suggesting that they underwent rigorous selection during breeding. At two loci (QKns.his-7D2–1 and QSl.his-5A-2) that the positive effects of the Bima4 alleles have been validated in the diverse panel, two and one kompetitive allele-specific PCR (KASP) markers were further developed, respectively, and they are valuable for marker-assisted selection breeding. Conclusion: Important chromosome regions controlling KNS and SL were identified in the founder parents. Our results are useful for knowing the molecular mechanisms of founder parents and future molecular breeding in wheat. [ABSTRACT FROM AUTHOR]

Spike length (SL) is the key determinant of plant architecture and yield potential. In this study, 193 recombinant inbred lines (RILs) derived from a cross between 13F10 and Chuanmai 42 (CM42) were evaluated for spike length in six environments. Sixty RILs consisting of 30 high and 30 low SLs were genotyped using the bulked segregant analysis exome sequencing (BSE-Seq) analysis for preliminary quantitative trait locus (QTL) mapping. A 6.69 Mb (518.43–525.12 Mb) region on chromosome 5AL was found to have a significant effect on the SL trait. Fifteen competitive allele-specific PCR (KASP) markers were successfully converted from the single nucleotide polymorphisms (SNPs) in the SL target region. Combined with four novel simple sequence repeat (SSR) markers, a genetic linkage map spanning 21.159 cM was constructed. The mapping result confirmed the identity of a major and stable QTL named QSl.cib-5A in the targeted region that explained 7.88–26.60% of the phenotypic variation in SL. QSl.cib-5A was narrowed to a region of 4.84 cM interval corresponding to a 4.67 Mb (516.60–521.27 Mb) physical region in the Chinese Spring RefSeq v2.0 containing 17 high-confidence genes with 25 transcripts. In addition, this QTL exhibited pleiotropic effects on spikelet density (SD), with the phenotypic variances proportion ranging from 11.34 to 19.92%. This study provides a foundational step for cloning the QSl.cib-5A, which is involved in the regulation of spike morphology in common wheat. [ABSTRACT FROM AUTHOR]

Background: In breeding programs, the selection of cultivars with the highest yield potential consisted in the selection of the yield per se, which resulted in cultivars with higher grains per spike (GN) and occasionally increased grain weight (GW) (main numerical components of the yield). In this study, quantitative trait loci (QTL) for GW, GN and spike fertility traits related to GN determination were mapped using two doubled haploid (DH) populations (Baguette Premium 11 × BioINTA 2002 and Baguette 19 × BioINTA 2002). Results: In total 305 QTL were identified for 14 traits, out of which 12 QTL were identified in more than three environments and explained more than 10% of the phenotypic variation in at least one environment. Eight hotspot regions were detected on chromosomes 1A, 2B, 3A, 5A, 5B, 7A and 7B in which at least two major and stable QTL sheared confidence intervals. QTL on two of these regions (R5A.1 and R5A.2) have previously been described, but the other six regions are novel. Conclusions: Based on the pleiotropic analysis within a robust physiological model we conclude that two hotspot genomic regions (R5A.1 and R5A.2) together with the QGW.perg-6B are of high relevance to be used in marker assisted selection in order to improve the spike yield potential. All the QTL identified for the spike related traits are the first step to search for their candidate genes, which will allow their better manipulation in the future. [ABSTRACT FROM AUTHOR]

The objective of this study was to identify quantitative trait loci (QTL) of spike length by association analysis with 94 doubled haploid wheat lines derived from Keumkang and Olgeuru. Days to heading date, culm length, spike length, and kernels per spike were evaluated in 2017 and 2018 in upland conditions. Culm length and spike length were biased short culm length and spike length (skewness=0.2 and 1.5, respectively). Kernel number per spike was biased low kernel number per spike (skewness=0.8). A genetic map was constructed with 170 microsatellite marker loci. One QTL was detected for spike length. The QTL on chromosome 4A, qSL-1 was detected by Xwmc283 and Xbarc327 explained 44.3% of the phenotypic variation. The QTL was applied to validate the relationship between genotypes of QTL and 29 Korean wheat cultivars grown for nine years under upland conditions. Korean wheat cultivars were classified into 5 types b ased on the combination of the two SSR markers. In Korean wheat cultivars, genotype b at Xbarc327, which was homozygous to Keumkang, had a shorter spike length (7.48 cm) than genotype c, which was different from the genotypes of Keumkang and Olgeuru, (8.45 cm). The two Korean wheat cultivars with genotypes ac at Xwmc283 and Xbarc327 had longer spike length (8.45 cm) than genotypes ba and bb (<7.42 cm). [ABSTRACT FROM AUTHOR]

This study was conducted to identify the storage characteristics of spikes of five bread wheat cultivars (Abu-Ghraib3, IPA-99, Boohooth-22, Al-Rashid and Al-Wafeer). These spikes were gathered and compacted in cubic box (25×25×25 cm) with different weight masses (0, 3, 6 and 9 kg container-1). A laboratory experiment was carried out in the Seed Technology Laboratory, Department of Field Crop Sciences, College of Agricultural Engineering Sciences-University of Baghdad. Results revealed significant differences among cultivars, masses levels and their interaction for all studied characters. Abu-Ghraib3 gave the highest mean of spikes number and less mean for the broken spikes and shuttered grains. While Al-Wafeer gave the highest mean of total grains weight resulted from spikes shuttering and grains space. However, Al-Rashid gave the highest mean of broken spikes, shuttered grains and replacement percentage in the container. Increasing the weight masses imposed on the gathered spikes in the container increased all studied characters. It can be concluded that the varieties were different in their spikes morphological characteristics as smaller spikes sizes the less losses resulted from spikes pressure. [ABSTRACT FROM AUTHOR]

The permanent need for efficient plant breeding comes from the increment of human population, which is projected to reach 9.7 million by 2050. Novel approaches could be used to reach these goals more rapidly, raising the question of efficiency, as well. Spike length is one of the important components of grain yield formation in wheat. The influence of individual plan traits is getting more important to grain yield formation per area unit in stressful growing conditions, which are increasingly present due to global climate changes. The objectives of the present research were three-fold: (i) to determine the influence of a genotype, environment and their interaction on spike length and to evaluate stability of the trait; (ii) to present cause-causing links on a graphical example; (iii) to transform a number of possibly correlated variables into a smaller number of uncorrelated variables called principal components. Samples were obtained from 96 winter wheat cultivars grown in 2011/12 and 2012/13 on two locations. The wheat genotype population was profiled with 28 microsatellites. The ANOVA of the total phenotypic variation of the experiment shows that genotypes took the largest portion, followed by the influence of the GE interaction. Additional analysis of the GE interaction using the PCA analysis shows a statistical significance of the first two main components. In the conducted research, the dispersion of the points represents two subpopulations, but the geographical origin could not explain the grouping of genotypes within the same, so the division into two groups was done on the basis of their lines of descent. [ABSTRACT FROM AUTHOR]

Italian ryegrass (Lolium multiflorim L.) is a short-term grass species that is of great importance for the production of quality fodder on arable land. It is grown in pure sowing or in short-term grass-leguminous mixtures. For the sowing of grasslands in Bosnia and Herzegovina, the significant seed quantities of the Italian ryegrass are used. The aim of this paper is to examine the yield variability and yield components of the progeny of the own selection of Italian ryegrass "BL Vubo" in relation to the four varieties of the Italian ryegrass that are most often used in our area. The research was carried out in the testing field and in the laboratories of the Agricultural Institute of the Republic of Srpska in Banja Luka during 2014 and 2015. These tests include the local selection "BL Vubo" and 4 foreign and local diploid and tetraploid varieties of the Italian ryegrass: Tur, Danergo, Draga and Tetraflorum. During the study, the following properties were monitored: number of generative stems per plant, spike length, number of spikelets per spike and seed yield per plant. During the two-year study, the highest average number of generative stems per plant was found in the Draga variety (183,6) and the lowest in the Tur variety (158,2). The average length of the Italian ryegrass in the tested genotypes varied from 23,4 cm (Draga) to 29,5 cm (Tetraflorum). The highest average number of spikelets/spike was found in the Tur variety (27,1). When it comes to yield of seeds/plants, the variety Draga (72,4 g) and the local selection "BL Vubo" (68,8 g) were distinguished. The variety had a highly significant influence on all tested properties (p<0,01). For the spike length, it is determined that year had highly significant influence (p<0,01), while for the rest of the examined properties, the effect of the year was significant (p<0,05). The existence of an interaction genotype x year has not been determined for any property. [ABSTRACT FROM AUTHOR]

A field experiments were carried out at the Abu- Graib Research Station - Office of Agricultural Research Ministry of Agriculture, to investigate moisture depletion effect for some traits of selected genotypes during 2014-2015, which depended to the long term of breeding program (2008-2014). The 9th selected genotypes and the control variety IPA 99 were evaluated during season 2015-2016 using split plot arrangement within RCBD and three replications. The main plots included four levels of water stress (20%, 40%, 60% and 80%), depletion of available water while, genotypes occupied sub plots.The results revealed significant differences among depletion %, genotypes and their interaction in all studied characters. Moisture depletion 20% of available water indicated the superiority of number days to 50% flowering (110.3 days), plant height (98..29 cm), flag leaf area (34.8 cm2), flag leaf angle (67.700), number days to 100% physiological maturity (146.53 days), spike length (11.53 cm), number of spikelets spike-1 (18.07), grain yield (5.06 t ha-1) and highest water use efficiency (1.63 kg m-3). The lowest value of the characters were found by depletion 80% of available water. The genotype 179 to took highest number of days to 50% flowering (114 days), IPA99 had highest flag leaf area (33.21 cm2) and highest period of 100% physiological maturity (145.75 days), genotype 27 had highest plant height (102.11 cm) and 186 produced highest spike length (11.75 cm), highest number of spikelests spike-1 (19.58), highest yield (5.64 t ha-1). Significant differences were found in interactions between genotypes and water stress in most characters studied, this shows of genotypes tolerance differences to water stress. So we can select one or more genotype , which tolerance to 20% moisture depletion. [ABSTRACT FROM AUTHOR]

An experiment was conducted at Research Station, State Board for Seeds Testing and Certification, Baghdad, Iraq during 2015-2016 and 2016-2017 seasons to determine the effect of four sowing dates (20th October, 10th November, 30th November and 20th December) on grain yield and it's components of three wheat cultivars (Bohooth 22, Bohooth 158 and Rasheed). The experiment was laid out in Randomized Complete Blocks Design (RCBD) within split plot arrangement. Sowing dates distributed in main plots and cultivars in sub plots with three replications. Sowing date 10th November was superior in grain yield (4.96 and 5.21 t ha-1) and most of its components (number of spikes 403.3 and 408.6 spike m-2 and number of spikelets per spike 22.08 and 22.26 spikelet spike-1 and number of grains per spike 56.37 and 58.63 grain spike-1), and some other traits (number of tillers 448.6 and 442.0 tiller m-2 and spike length 15.84 and 14.39 cm) for both seasons, respectively, whereas sowing in 20th October was superior in 1000 grain weight (42.94 and 43.72 g) for both seasons, respectively. Cultivar Rasheed was superior in grain yield (4.50 and 4.71 t ha-1) and most of yield components (number of spikes 389.5 and 397.3 spike m-2 and number of spikelets per spike 22.52 and 22.59 spikelet spike-1 and 1000 grain weight 41.61 and 43.02 g) and in some other traits (number of tillers 428.7 and 432.4 tiller m-2 and spike length 17.27 and 16.69 cm) for both seasons, respectively. It's clear from the results that 10th November is the best sowing date at central Iraq to get highest grain yield, and the early or late sowing could be decrease the grain yield, although the effect of early sowing is greater than the effect of late sowing on this trait in wheat. [ABSTRACT FROM AUTHOR]

Two field experiments were carried out at field crop research station- Abu-Ghraib- agricultural researches office during 2014-2015 and 2015-2016 to investigate effect of irrigation deficiency quantities and ABA concentrations soaking and spraying on yield, its components of bahooth 10 wheat cultivar. Split plot arrangement by RCBD with three replicates for each experiment. First trial included for water irrigation quantities which control treatment (50% water depletion from available water), 70% and 40% from control treatment as well as rainy treatment (germination irrigation + rainfed) which occupied main plots while ABA soaking concentration (0, 1, 2, and 3) micromoles which occupied sup plots. Second experiment included same irrigation treatments which occupied main plots while ABA spraying concentration (0, 30, 60 and 90) micromoles occupied sub plots. The results of first experiment revealed there is no significant differences between the control treatment and 70% of the control for the number of spikelet per spike 18.79 and 18.45 spikelet Spike-1, number of spike 331.99 and 330.54 spike m-2, grain yield 4.73 and 4.74 ton ha-1 as average for both season respectively. The results of second experiment showed that control treatment attained the highest values of number of spike 328.25 and 333.92 spike m-2, grain yield 4.97 and 5.11 ton ha-1 for both season respectively, but didn’t differ 70% from control treatment. Concentrations soaking and spraying of ABA affect significantly most of studied traits. 3 micromoles Soaking concentration gave the highest values for number of spikes 309.00 and 310.25 spike m-2, number of grain per spike 49.81 and 51.18 grain Spike-1, grain yield 3.62 and 3.97 ton ha-1 for both season respectively, spraying with ABA at 60 micromole concentrations gave the average number of spike 326.00 and 332.00 spike m-2, grain yield 3.85 and 4.18 ton ha-1 for both season respectively with no significant difference with 90 micromole concentration which gave the highest values. The interaction between irrigation and ABA (soaking and spraying) showed a significantly effect on most characteristics yield and its components. Therefore can be conclude to capability of irrigation with 70% from full irrigation without signification effect in grain yield, as well as can be treat plant wheat with ABA concentration 3 and 60 micromoles soaking and spraying respectively to improve their ability to tolerance water stress. [ABSTRACT FROM AUTHOR]

Field experiments were conducted over three growing seasons, during 2009-2012, at the experimental farm of Field Crop Sciences - College of Agriculture - University of Baghdad. This study aimed to application pure line selection in fifteen F4 segregating populations of bread wheat produced from half diallel crossing among 6 parents.The selection was applied in the first season by using 10% selection intensity, further screening was conducted and selected 12 plants from each population .The grains of individual selected plants were planted in the following year in plant to row method and the best 15 progeny lines were selected depending on yield performance. Varietal trail was conducted in the third season as RCBD with four replications using a split plot arrangement, where three seed rates (120, 160, and 200 kg.ha-1) randomized in the main plots and 21 genotypes in the sub-plots. The genotypes included fifteen F6 progeny lines plus six parents: Al-fatah, A3103, M.2, IPA99, A4.10, and Abu-Ghraib3. The results showed significant differences among genotypes, seeding rates and interaction between them for all the traits. It was revealed the superiority of progeny lines S123, S102, S52, S130, S148 and S83 over the best cultivars, they yielded 6.64, 6.41, 6.34, 6.16, 6.11 and 6.11t.ha-1 respectively.The progeny S123 superior significantly to other best progenies in grain yield and biological yield. The highest harvest index produced from using 160 kg.ha-1 seeding rate. Response of grain yield to seeding rates was quadratic relation. Highly significant differences were found among the genotypes under the three seed rates for all traits, indicating relatively high magnitude of genetic variability in these genotypes. [ABSTRACT FROM AUTHOR]

The aim of this field study was to evaluate genotype x year interaction for spike length, 1000 seed weight, seed number per g and hectoliter mass in perennial ryegrass, using eight divergent genotypes across two growing seasons. Interaction was evaluated using AMMI (Additive Main Effects and Multiplicative Interaction) model. All traits schowed additive (genotype, year) and non additive (genotype x year interaction) variation. On the basis od AMMI1 biplot genotype G4 showed most stability for all examined traits, so it can be recommended for sowing in different environmental conditions. Also, the genotype G4 could be used in the creation of new local varieties of perennial ryegrass. [ABSTRACT FROM AUTHOR]

Spike length (SL) is one of the most important components of spike morphology, and the uppermost internode represents an ideal organ to study the transportation system. We performed conditional and unconditional quantitative trait locus (QTL) mapping in two unrelated recombinant inbred line populations to precisely detect QTLs for uppermost internode length (UIL) and SL, and to dissect the genetic relationship between these two factors with plant height (PH). Both of the populations were derived from crosses with synthetic wheat. Ten repetitive QTLs for UIL and six environment-independent QTLs for SL were identified in this study, and twelve of these were completely independent of PH. Conditional QTL mapping analysis indicated that SL was more independent to PH than UIL was. The results indicated that the conditional QTL mapping method could evaluate PH component effects on PH, and thus accelerate the selection of suitable loci that improve commercial wheat morphology yet avoid changes to PH. [ABSTRACT FROM AUTHOR]

The spike characteristics length, spikelet density and fertile floret number are related yield components and are important in cereal improvement. QSpl.nau- 2D is a major quantitative trait locus controlling spike length (SPL) detected in the recombinant inbred line population developed by crossing wheat ( Triticum aestivum) cultivars Nanda2419 with Wangshuibai. In this study, to validate its genetic effect and determine its precise location, QSpl.nau- 2D's near-isogenic line (NIL) was developed using Mianyang99-323 as the recurrent parent through marker-assisted selection. Field trials showed that the NIL not only had significantly longer spikes on average than the recurrent parent but also had significantly higher grain weight, but did not differ in spikelet number and kernel number per spike. In the F2 population derived from a cross of the NIL with Mianyang99-323, QSpl.nau- 2D functioned like a single gene and conditioned the SPL in a partially dominant manner, and was thus designated as HL1 (for head length). To precisely map HL1, 89 recombinants, consisting of 11 genotypes, were identified in the NIL-derived F2 population of 674 plants by using markers in the Xwmc25- Xgpw4080 interval. Phenotyping these lines showed that the introduction of a 0.9-cM interval flanked by Xcfd53 and DG371 in Nanda2419 resulted in longer spikes and a higher grain weight in the NIL. The availability of markers closely linked to HL1 could facilitate its use in breeding programs. [ABSTRACT FROM AUTHOR]

The genetic studies were conducted on six new winter wheat (Triticum aestivum L.) line during three years investigations developed in agro ecological conditions of Kosovo. Data for various morphological and yield traits were taken and analyzed for spike length (SL), plant height (PH), total dry matter (TDM), spike Weight (SW), grain weight per spike (GWS), yield (Y) and harvest index (HI). Field design consisted in a randomized blocks design (RBD) with three replications. Results indicated that the line 01KS as the most competitive genotypes produced significantly higher for SL (9.58 cm), GWS (2.37 g per spike) and grain yield (10.66 t ha-1) while lower yield was recorded at the line 04KS (8.02 t ha-1). The lowest SL (8.4 cm) belonged to line 06KS which was ranked as the least competitive genotype. The significantly higher total dry matter (TDM) was recorded at the wheat line 02KS on value 4.88 g, while the lowest (4.44 g) belonged to 04KS which was ranked as the last genotype. There was a positive and significant harvest index (HI) on value from 50.5% to 39.1%. [ABSTRACT FROM AUTHOR]

Flowering time is a trait which has a major influence on the quality of forage. In addition, flowering and subsequent seed yields are important traits for seed production by grass breeders. In this study, we have identified quantitative trait loci (QTL) for flowering time and morphological traits of the flowering head in an F1 mapping population in Lolium perenne L (perennial ryegrass), a number of which have not previously been identified in L. perenne mapping studies. QTL for days to heading (DTH) were mapped in both outdoor and glasshouse experiments, revealing three and five QTL for DTH which explained 53% and 42% of the total phenotypic variation observed, respectively. Two QTL for DTH were detected in both environments, although they had contrasting relative magnitudes in each environment. One QTL for spike length and three QTL for spikelets per spike were also identified explaining, a total of 32 and 33% of the phenotypic variance, respectively. Furthermore, the QTL for spike length and spikelets per spike generally coincided with QTL for days to heading, implying co-ordinate regulation by underlying genes. Of particular interest was a region harbouring overlapping QTL for days to heading, spike length and spikelets per spike on the top of linkage group 4, containing the major QTL for spike length identified in this population. [ABSTRACT FROM AUTHOR]

Selection criteria for drought tolerance would be helpful tools for wheat breeding programmes. To assess the usefulness of some morphological traits above the flag leaf node as indicators of yield and the susceptibility index (SI) of Fischer and Maurer, 10 durum wheat genotypes were used in experiments conducted under two water regimes at two latitudes in Spain during 3 years. Morphological traits were measured at anthesis, and yield, yield components and quality traits were evaluated at ripening. Principal components analysis showed associations between morphological traits and yield, yield components and quality, most of them caused by differences between environments. Peduncle weight, spike weight and length and awn length were significantly related to SI within environments. Spike and peduncle weight were the traits more related to yield and SI in all the experiments together and in the rainfed sites, while in the irrigated sites spike length was better. The spike weight and length were negatively associated with SI, while peduncle weight was positively associated to SI. Genotype means across all experiments were associated with SI values. These morphological traits could be selection criteria in breeding programmes to obtain varieties with good yield stability. The genetic variability found suggests opportunity for selection. [ABSTRACT FROM AUTHOR]

A doubled-haploid (DH) population from an intervarietal cross between the Japanese cultivar 'Fukuho-komugi' and the Israeli wheat line 'Oligoculm' was produced by means of wheat × maize crosses. One hundred seven DH lines were genotyped to construct a simple sequence repeat (SSR) based linkage map with RFLP, RAPD, and inter-simple sequence repeat markers. Out of 570 loci genotyped, 330 were chosen based on their positions on the linkage map to create a "framework" map for quantitative trait locus (QTL) analysis. Among the 28 linkage groups identified, 25 were assigned to the 21 chromosomes of wheat. The total map length was 3948 cM, including the three unassigned linkage groups (88 cM), and the mean interval between loci was 12.0 cM. Loci with segregation distortion were clustered on chromosomes 1A, 4B, 4D, 5A, 6A, 6B, and 6D. After vernalization, the DH lines were evaluated for spike number per plant (SN) and spike length (SL) in a greenhouse under 24-h daylength to assess the "gigas" features (extremely large spikes and leaves) of 'Oligoculm'. The DH lines were also autumn-sown in the field in two seasons (1990–1991 and 1997–1998) for SN and SL evaluation. QTL analysis was performed by composite interval mapping (CIM) with the framework map to detect QTLs for SN and SL. A major QTL on 1AS, which was stable in both greenhouse and field conditions, was found to control SN. This QTL was close to the glume pubescence locus (Hg) and explained up to 62.9% of the total phenotypic variation. The 'Oligoculm' allele restricted spike number. The SSR locus Xpsp2999 was the closest locus to this QTL and is considered to be a possible marker for restricted tillering derived from 'Oligoculm'. Eight QTLs were detected for SL. The largest QTL detected on 2DS was common to the greenhouse and field environments. It explained up to 33.3% of the total phenotypic variation. The second largest QTL on 1AS was common to the greenhouse and the 1997–1998 season. The position of this QTL was close to that for the SN detected on 1AS. The association between SN and SL is discussed. [ABSTRACT FROM AUTHOR]

Spike length (SL), fertile spikelet number per spike (SNS), thousand grain weight (TGW) and plant height (PH) are important agronomic traits related to yield in wheat. By the 55 K SNP assay, we constructed a high-density genetic linkage map with 186 F6 recombinant inbred lines developed between Chinese landrace wheat Banmangzi and an elite variety Jimai 22. Eighteen QTLs for SL, SNS, TGW and PH were detected. A new stable major QTL for SL was located on chromosome 2DS, with physical position 19.6 Mb and explaining 20.1–27.9% of the phenotypic variances in three environments, with the favorable allele from Banmangzi. And the QTL was co-located with QSNS.saas-2D.1 and QPH.saas-2D.2 which were detected in two environments and explained up to 18.5% of phenotypic variances for SNS. In addition, an major QTL for TGW was detected on chromosome 6AS, explaining 14.6–22.3% of the phenotypic variances in three environments. Four candidate genes for yield-related traits were identified, encoding IAA-amino acid hydrolase ILR1 and growth-regulating factor for SL, flowering promoting factor-like 1 and sucrose-phosphate synthase for TGW, respectively. [ABSTRACT FROM AUTHOR]

Dasypyrum breviaristatum (genome VbVb) contains potentially important traits for commercial wheat production. Chromosome 2Vb of D. breviaristatum carries several desirable agronomic characters, including long spike length as well as enhanced resistance to stripe rust, which are expressed in a common wheat background. In this study, wheat-D. breviaristatum 2Vb deletion lines were produced and identified by fluorescence in situ hybridization (FISH), and 74 molecular markers specific to D. breviaristatum chromosome 2Vb were physically localized in 4 distinct chromosomal regions. New wheat-D. breviaristatum 2Vb translocation lines were also characterized by FISH. The breakpoint of the translocation T3AS.3AL-2VbS was determined by physically mapped molecular markers. Field evaluation revealed that genes affecting plant height and spike length are located on fraction length (FL) 0.65-1.00 of 2VbS, while the stripe rust resistance gene(s) are located on FL 0.40-1.00 of D. breviaristatum chromosome 2VbL. The newly characterized wheat-Dasypyrum chromosomal introgressions are of potential value for the improvement of the yield and disease resistance of wheat. [ABSTRACT FROM AUTHOR]

Dasypyrum breviaristatum (genome VbVb) contains potentially important traits for commercial wheat production. Chromosome 2Vb of D. breviaristatum carries several desirable agronomic characters, including long spike length as well as enhanced resistance to stripe rust, which are expressed in a common wheat background. In this study, wheat-D. breviaristatum 2Vb deletion lines were produced and identified by fluorescence in situ hybridization (FISH), and 74 molecular markers specific to D. breviaristatum chromosome 2Vb were physically localized in 4 distinct chromosomal regions. New wheat-D. breviaristatum 2Vb translocation lines were also characterized by FISH. The breakpoint of the translocation T3AS.3AL-2VbS was determined by physically mapped molecular markers. Field evaluation revealed that genes affecting plant height and spike length are located on fraction length (FL) 0.65-1.00 of 2VbS, while the stripe rust resistance gene(s) are located on FL 0.40-1.00 of D. breviaristatum chromosome 2VbL. The newly characterized wheat-Dasypyrum chromosomal introgressions are of potential value for the improvement of the yield and disease resistance of wheat. [ABSTRACT FROM AUTHOR]