Assessment of the relationship of yield and its contributing traits in wheat

Wheat is an essential source of nutrition for humans and an important cereal crop of Pakistan due to its widespread use as food. To fulfill the nutrition needs of boosted population, crop yield must be improved. In this perspective, we conducted the experiment reported in this paper to achieve correlation and path coefficient attributes given by yield-related traits. Our study enables to understand the association and contribution of nine traits toward grain production. The genetic material was comprised of seven parents and twelve F1 hybrids. Correlation analysis showed that grain yield per spike, thousand grain weight, spike length, and number of tillers per plant have positive and significant correlation with grain yield per plant, at both genotypic and phenotypic level. Path coefficient analysis revealed that direct effects of number of tillers per plant, grain yield per spike, and spike length were positive. This data persuaded that selection based on these traits could be useful for breeding purposes to higher grain yield.

The Effect of the Application of Stimulants on the Photosynthetic Apparatus and the Yield of Winter Wheat

The use of stimulation preparations seems to be a promising means for mitigating the effects of abiotic and biotic stressors. Their significance includes plant organism stimulation and metabolism optimisation, water regime, and nutrition during periods of stress. They help bridge it over and create conditions for rapid regeneration. In a field experiment, the effect of the application of stimulation preparations on cultivars Triticum aestivum L. with different genetic composition was evaluated (donor of blue aleurone colour KM-72-18; donor of a multi-row spike (MRS) KM-94-18). Our results show a predominantly positive effect of the application of stimulants on the yield and thousand-grain weight (TKW). The results obtained were influenced by the year, based on different temperatures and precipitation. Higher yields were achieved in 2020 with higher total precipitation during the grain filling period and with a higher maximum quantum yield of the photosystem II (Fv/Fm). In 2019, this period was significantly dry and warm, which was reflected in a lower yield and TKM, higher proline content in the leaves, and lower Fv/Fm values. In both experimental years, there was a higher yield of the cultivar with blue aleurone (KM-72-18). In the case of cultivars with coloured grains, the promising use of the content substances in cultivars as natural means of increasing resistance to abiotic and biotic stressors seems to be promising.

FERTILISATION SOURCE AND DOSE OPTIMISATION BOOST YIELD OF DURUM WHEAT IN MEDITERRANEAN CLIMATIC CONDITIONS

Climate change, global warming, environmental pollution, greenhouse gas emissions from agricultural fields, stagnant wheat yields and reduced farm economic returns require optimisation of sources and doses of plant nutrients. A field study was conducted to evaluate wheat response to different forms of fertilisers and nitrogen (N) doses under Mediterranean conditions. The field trial was comprised of fertiliser sources, including chemical fertilisers, compost and leonardite, while different nitrogen levels (0, 80, 160, 240 kg ha-1) were also tested. The experimental variables included yield attributes (height of the, length of the spike, spikelets number per spike, thousand-grain weight and grain yield). In addition, nutritional quality attributes like protein and starch contents were studied along with NDVI values of wheat under different fertilisation regimes. The trial was executed using a randomised complete block (factorial) design using four replications. The results revealed that fertiliser forms and N doses remained ineffective for boosting yield attributes of wheat. For nutritional characteristics of wheat grains, a higher N dose remained instrumental in boosting protein, starch and wet gluten contents. Thus, 240 kg ha-1 of N dose might be recommended for general adoption under Mediterranean conditions; however, study findings are limited in scope and further in-depth studies are needed by testing organic manures from plant and animal origins.

Control of Thousand-Grain Weight by OsMADS56 in Rice

Grain weight and size are important traits determining grain yield and influencing grain quality in rice. In a previous study, a quantitative trait locus controlling thousand-grain weight (TGW) in rice, qTGW10-20.8, was mapped in a 70.7 kb region on chromosome 10. Validation of the candidate gene for qTGW10-20.8, OsMADS56 encoding a MADS-box transcription factor, was performed in this study. In a near-isogenic line (NIL) population segregated only at the OsMADS56 locus, NILs carrying the OsMADS56 allele of IRBB52 were 1.9% and 2.9% lower in TGW than NILs carrying the OsMADS56 allele of Teqing in 2018 and 2020, respectively. Using OsMADS56 knock-out mutants and overexpression transgenic plants, OsMADS56 was validated as the causal gene for qTGW10-20.8. Compared with the recipients, the TGW of the mutants was reduced by 6.0–15.0%. In these populations, decreased grain weight and size were associated with a reduction in the expression of OsMADS56. In transgenic populations of OsMADS56 driven by a strong constitutive promoter, grain weight and size of the positive plants were significantly higher than those of the negative plants. Haplotype analysis showed that the Teqing-type allele of OsMADS56 is the major type presented in cultivated rice and used in variety improvement. Cloning of OsMADS56 provides a new gene resource to improve grain weight and size through molecular design breeding.

Physico-chemical properties of grain of different ripening soft winter wheat varieties under different fertilizer systems

Aims. To determine the formation of physico-chemical properties of different ripening varieties of soft winter wheat grain under different fertilizer systems in a field crop rotation. Methods. Laboratory, mathematical and statistical, physicochemical. Results. The article presents the formation of physico-chemical properties (thousand grain weight, grain unit, hardness index, protein content) of different ripening varieties of soft winter wheat grain under different fertilizer systems in the field crop rotation. On average, over two years of research, thousand grain weight of KWS Emil soft winter wheat increased from 37.2 to 38.5 g, depending on the fertilizer system. The use of all types of fertilizers increased it by 3 % compared to areas without fertilizers. There is no significant difference between fertilizer application systems in the field crop rotation. The high stability index (0.96–1.00) of thousand grain weight formation under growing both varieties indicates a slight influence of weather conditions of the growing season. Thus, in 2020 this figure increased from 37.1 to 38.3 g, and in 2021 – from 37.2 to 39.1 g. In Rino variety, thousand grain weight was significantly higher than in KWS Emil variety by 16–17 %. The application of 75 kg/ha of nitrogen fertilizers increased it from 43.2 g to 43.6–43.8 g or only by 1 %, and at a double dose – to 44.8–45.2 g, or by 4–5 %. The efficiency of phosphorus-potassium fertilizers was higher than the cultivation of KWS Emil, and lower in Rino. The grain unit of both soft winter wheat varieties increased both on average and over the years of research with a stability index of 0.98–1.00. Thus, on average over two years of research, it increased in KWS Emil variety from 771 to 779–789 g/l or 1–2 % depending on the fertilizer system. Rino grain had 6% more grain unit compared to KWS Emil. On average, it increased from 820 to 831–838 g/l per fertilizer application or only by 1–2 %. Conclusions. It is established that the physico-chemical properties of grain change depending on the fertilizer system, variety and weather conditions of the growing season. Rino grain has higher physico-chemical properties. Thus, thousand grain weight increases from 43.2 to 43.6–45.2 g, grain unit – from 820 to 831–838 g/l, protein content – from 14.4 to 15.4–16.4 %, depending on the fertilizer system, hardness type – hard-grained. In KWS Emil variety, thousand grain weight increases from 37.2 to 38.3–38.5 g, grain unit – from 771 to 779–789 g/l, protein content – from 11.7 to 12.3–13.7 % depending on the fertilizer system, hardness type – soft-grained.

Detection of drought tolerance-related QTL in the Plainsman V./Cappelle Desprez doubled haploid wheat population

Drought stress is one of the major abiotic factors that significantly reduces wheat grain yield. Improving drought tolerance is a challenge that plant breeders are facing nowadays. In this study, our goal was to identify quantitative trait loci (QTL) in the Plainsman V./Cappelle Desprez doubled haploid (DH) population under drought induced as decreased irrigation (ds) and well-watered (ww) conditions in glasshouse. In total, 54 QTL were detected across the three years in two water regimes linked to 10 drought tolerance-related agronomic traits. Out of the detected QTL regions several have been previously reported. The QTL on chromosome 1A (wPt-744613-wPt-8016) related to thousand grain weight was detected in both ds and ww conditions, explaining the 12.7–17.4% of the phenotypic variance. QTL for grain yield was detected on chromosomes 1A, and 6B in the ds treatment. Numerous QTL was identified under both irrigation levels.

Evaluation of resources in the study of industrial and culinary properties for the varietal characterization of rice (Oryza sativa L.)

Different physicochemical tests have been used over time in the Oryza sativa species for the study of industrial and culinary properties. In this study, nine attributes were compared: amylose content, total whiteness, thousand grain weight, grain length and width, gelatinization time, apparent water absorption, expansion ratio, and gelatinization temperature. However, there is no single attribute that allows defining the concept of “culinary quality” in rice, since it depends on its behavior after cooking. The two varieties of long fine polished rice used for this study were: IRGA 424 (Rio Grandense Rice Institute) and Tranquilo FL INTA (National Institute of Agricultural Technology) and a mixture of both. In this work, the characterization of industrial and culinary properties of the rice varieties mentioned above was achieved by evaluating five attributes using simple and low-cost physical-chemical techniques in two of the rice varieties most in demand by producers in the province of Corrientes. This finding would allow the study of rice varieties to be approached by optimizing: equipment, reagents and time in future trials.

Genetic variability of some agronomic traits in a collection of wheat (Triticum turgidum L. ssp) genotypes under South Mediterranean growth conditions

Genetic variability of some agronomic traits were investigated in 60 tetraploid wheat accessions (Triticum turgidum L. ssp) under rainfed conditions. The results indicated the presence of sufficient variability for all measured traits.The highest phenotypic and genotypic coefficient of variation was recorded for yield and awn length. High heritability coupled with high genetic advance and high expected response to selection recorded for thousand-grain weight, awn length, and the number of grains per spike. Cluster analysis grouped the 60 wheat genotypes into five clusters. Clusters are relatively formed according to the geographical origin of the genotypes. Cluster III carried entries having the best combinations for all the traits; in which genotypes PI 127106, PI 192658, PI 29051 and PI67343 can represent an important reservoir of useful genes for the development of new wheat cultivars. Thousand-grain weight, biomass, awn length and harvest index could be used as a selection criterion for hybridization programs in the future. Highlights - The genetic variability of 9 traits of 60 wheat varieties was investigated. - There was great variability among wheat genotype for all measured traits. - There were wheat varieties shows highest phenotypic and genotypic coefficient of variation. - Some wheat genotypes may be desired allele reservoirs. - Some traits can be an alternative in wheat selection.

Functional Analysis of the “Green Revolution” Gene Photoperiod-1 and Its Selection Trends During Bread Wheat Breeding

Flowering is central to the transformation of plants from vegetative growth to reproductive growth. The circadian clock system enables plants to sense the changes in the external environment and to modify the growth and development process at an appropriate time. Photoperiod-1 (Ppd-1), which is controlled by the output signal of the circadian clock, has played an important role in the wheat “Green Revolution.” In the current study, we systematically studied the relationship between Ppd-1 haplotypes and both wheat yield- and quality-related traits, using genome-wide association analysis and transgenic strategies, and found that highly appropriate haplotypes had been selected in the wheat breeding programs. Genome-wide association analysis showed that Ppd-1 is associated with significant differences in yield-related traits in wheat, including spike length (SL), heading date (HD), plant height (PH), and thousand-grain weight (TGW). Ppd-1-Hapl-A1 showed increased SL by 4.72–5.93%, whereas Ppd-1-Hapl-B1 and Ppd-1-Hapl-D1 displayed earlier HD by 0.58–0.75 and 1.24–2.93%, respectively, decreased PH by 5.64–13.08 and 13.62–27.30%, respectively, and increased TGW by 4.89–10.94 and 11.12–21.45%, respectively. Furthermore, the constitutive expression of the Ppd-D1 gene in rice significantly delayed heading date and resulted in reduced plant height, thousand-grain weight, grain width (GW), and total protein content. With reference to 40years of data from Chinese wheat breeding, it was found that the appropriate haplotypes Ppd-1-Hapl-A1, Ppd-1-Hapl-B1, and Ppd-1-Hapl-D1 had all been subjected to directional selection, and that their distribution frequencies had increased from 26.09, 60.00, and 52.00% in landraces to 42.55, 93.62, and 96.23% in wheat cultivars developed in the 2010s. A Ppd-B1 methylation molecular marker was also developed to assist molecular wheat breeding. This research is of significance for fully exploring the function of the Ppd-1 gene and its genetic resource diversity, to effectively use the most appropriate haplotypes and to improve crop yield and sustainability.

Morphological variability and genetic diversity of Aman rice germplasm of Bangladesh cultivated in Mymensingh region

Thirty-one Aman rice germplasm were evaluated to assess their morphological variability and genetic diversity considering ten quantitative and thirty one qualitative traits at the field experimental plot of Bangladesh Institute of Nuclear Agriculture, Mymensingh, following randomized complete block design. The germplasm showed significant differences for all the studied traits. The highest grain yield/plant was recorded in Sentu-16 whereas the lowest was found in Gaindha. The genotypic coefficient of variation (GCV) was lower than those of the corresponding phenotypic coefficient of variation (PCV) for all the traits. High PCV and GCV along with heritability, genetic advance (GA) and GA in percentage of mean were recorded for number of filled grains/panicle and number of unfilled grains/panicle. Grain yield/plant had positively significant correlation with plant height, number of total tillers/hill, number of effective tillers/hill, number of filled grains/panicle and thousand grain weight. Path co-efficient analysis suggested that grain yield/plant had positive direct effect in association with days to fifty percent flowering, number of effective tillers/hill, panicle length, number of filled grains/panicle and thousand grain weight. Principal component analysis revealed that the first three components accounted for 79.57% of cumulative variance. Cluster analyses were revealed that the studied rice germplasm organized into five clusters based on D2 values where maximum inter-cluster distance was observed between cluster II and V. Qualitative characterization by distinctness, uniformity and stability test revealed that a wide range of variation was observed among the genotypes. Therefore, this study would be useful for breeders to choose and identify the revival and preservation of beneficial genes for crop improvement.