Selection Of Promising Genotypes Research Articles

Maize genetic breeding for tolerance to abiotic stress with focus on sustainable use of environmental resources

This bibliographic review explored maize genetic breeding to increase tolerance to abiotic stress. The main stresses faced by the crop, such as water stress and nitrogen deficiency, and their negative impacts on grain yield were discussed. Strategies to minimize these effects were examined, focusing on the selection of tolerant genotypes and the strategic positioning of these genotypes in different growing environments. The germplasm bank and genetic diversity were highlighted as crucial resources to identify desirable traits and genes associated with resistance to abiotic stress. The selection of secondary characters, considering their heritability and correlation with characters of interest, allows maximizing the efficiency in the selection of promising genotypes in genetic breeding programs. Test environments simulating stresses, such as water stress and low nitrogen, are essential to evaluate the performance of genotypes and identify the most tolerant ones. The genetic breeding of maize for tolerance to abiotic stress promotes promising solutions to face environmental challenges and ensure the sustainability of agricultural production.

Genotypic variation of yield-related traits in an irrigated rice breeding program for tropical Asia

Developing high-yielding rice varieties is critical to ensure global food security. To date, selection of promising genotypes is based on empirical evaluation for grain yield, but the relationship of agronomic traits to yield in tropical rice breeding is largely unknown. This study aimed to determine the extent of variation for 19 agronomic traits and interrelationships among traits in an irrigated rice breeding program at the International Rice Research Institute, Philippines. A large set of elite germplasm comprising advanced genotypes and varieties derived from the breeding pipeline was evaluated during dry and wet seasons. The broad-sense heritability ranged from 0.35 to 0.99 for all traits in both seasons. Grain yield for the whole plot (plot yield) was positively correlated with yield per plant, 1000 grain weight, and grain width in dry season, and yield per plant, 1000 grain weight, grain width, number of panicles per plant, and panicle exertion rate in wet season. Path analysis showed that the highest direct positive effect of traits on plot yield ranged from 0.25 to 0.45 in dry season and from 0.22 to 0.88 in wet season. Heat map bi-cluster analysis assigned genotypes into three main clusters in both seasons, while traits were grouped into three and five clusters in dry and wet seasons, respectively. The cluster analysis showed that spikelets per panicle, filled grains per plant, and yield per plant were key yield contributing traits. Identification of traits that were highly correlated with rice yield could be useful for developing new varieties adapted to tropical environments.

Multi-Trait Selection Indices for Identifying New Cassava Varieties Adapted to the Caribbean Region of Colombia

In Colombia, the highest cassava production comes from the semi-arid region of the Atlantic Coast with relatively low yield for fresh consumption (≤11 t/ha). Development of improved varieties is based on a plant ideotype which integrates a group of desirable traits independently measured in the field. However, selecting high performance genotypes for several traits simultaneously is a complex process. Sixteen genotypes were evaluated under four environmental conditions (localities) of the Colombian Caribbean region (Cereté, Carmen de Bolivar, Agustín Codazzi, and Sevilla), and two production cycles (2016/2017–2017/2018) in order to assess phenotypic expression of selected traits, their stability, and utility in genotype selection. Selection of promising genotypes should consider both their superiority and stability. Genotypes SM3106-14, GM1692-56, CM9456-12, and GM214-62 were selected based on their agronomic performance. In addition, frequency analysis of sensorial data showed that genotypes CM9456-12, SM1127-8, SM3553-27, and SM3562-32 were preferred by panelists who assessed, color, flavor, texture, and root shape. Determination of superiority through across-environments, multi-trait selection index allows identifying genotypes with superior performance. However, selection was improved when local multi-trait selection indices were included—phenotypic stability determination (through Lin and Binns index and AMMI model) supported an adequate selection of superior and stable cassava genotypes. The inclusion of palatability response and quality features determination in cassava genotypes can be recommended to identify genotypes with higher adoption rates by farmers and consumers.

Stability of Wheat Genotypes by AMMI and Yield Evaluated under Peninsular Zone of India

Background: Efficient estimation of main and interaction effects under multi environment trials had been carried out by AMMI. Studies with low proportion of the variance explained by first interaction principal component IPCA1 under AMMI analysis had been reported biased interpretation for the stability of the genotypes.Methods: Weighted Average of Absolute scores (WAASB), quantitative stability measure had been recommended for selection of productive genotypes with broad adaptation. The selection of promising genotypes had been assisted by use of superiority index (WAASBY) that considered simultaneous use of yield and stability by allowing variable weighting mechanism for yield and stability.Result: Wheat GW509 and HI1633 genotypes had been identified by stability measure WAASB for the first year. While Superiority index considered stability and high yield settled for HI1633 and Raj4083 genotypes. Analytic measures of adaptability PRVG and MHPRVG observed suitability of HI1633 and Raj 4083. SI expressed positive linear behaviour with yield, MHPRVG and PRVG measures. While stability measure WAASB maintained moderate negative correlation with yield, SI, MHPRVG and PRVG. Wheat genotypes HI1633, HI1641 and HI1646 identified by stability measure for the next year of study. Superiority index selected HI1641, HI1633 and MACS6752 genotypes. SI expressed direct linear relation with yield, MHPRVG and PRVG. Stability measure exhibited indirect relationships with SI, MHPRVG, PRVG and yield Wheat genotypes HI1633, Raj 4083 for first year and HI1641, MACS6752 for the second year of study.

Biometric characteristics of fruits and leaves of Cornus officinalis Siebold et Zucc. genotypes in the M.M. Gryshko National Botanical Garden of the NAS of Ukraine

In the context of global climate change, the current strategy of agroeconomics focuses on the introduction of unique plant species and the selection of new commercially important cultivars adapted to the dramatic weather changes. Cornus officinalis (Cornaceae) has Chinese origin, its reintroduction at the M.M. Gryshko National Botanical Garden, National Academy of Sciences of Ukraine started in 1993.
 The objectives of this research were: to investigate the biometric parameters of fruits and leaves of C. officinalis genotypes, C. officinalis × C. mas hybrid ‘Etude’ and genotype from the grafting C. officinalis on C. mas under cultivation in the M.M. Gryshko National Botanical Garden, National Academy of Sciences of Ukraine, and to determine the degree of adaptation of C. officinalis to the climatic conditions of Ukraine (in particular, Right-Bank Forest Steppe) for selection of promising genotypes for further breeding work.
 Material and methods. We used: a) 26-year-old maternal plant obtained from a two-year-old seedling in 1993 received from the nursery “Northwoods Wholesale Nursery” Mollala (Oregon, USA), where it was grown as an ornamental plant; b) seedlings of the maternal plant; c) cultivar Etude, which is an artificial hybrid from crossing C. officinalis × C. mas; and d) genotype obtained from grafting C. officinalis on C. mas. In our experiment, the maternal plant is indicated as G-01, while other plants – as G-02–G-08 genotypes. We determined the biometric parameters of the fruit (length, diameter, and weight), endocarp (length, diameter, and weight), pedicel (length and thickness), leaf blade (length, width, and the number of lateral veins) and petiole (length, width, and thickness). We examined the dynamics of fruit and endocarp formation during the season (genotypes G-01–G-03 and G-05) and compared the biometric characteristics of the fruit of genotypes G-01–G-05 from crops of two years, 2010 and 2018, which were most favorable in weather conditions. We have processed quantitative data in the PAST 2.10 software. The differences between the samples were estimated using the Tukey-Kramer test. The degree of variability was determined by the coefficient of variation. To assess the level of variability, we used the classification of Mamaev (1975).
 Results. We have found that the largest fruits in 2010 were observed in the genotype G-01 and the smallest – in the genotype G-03. The coefficient of variation of the linear parameters of the fruit and endocarp was in the range 5.7–10.1 %; the level of variability was very low or low. The variability of fruit weight and endocarp was high; the coefficient of variation was from 7.0 up to 28.3 %. The amplitude of the linear parameters of the leaf was wide (coefficient of variation was from 9.8 to 31.0 %). The cultivar Etude differed from other C. officinalis genotypes in size and weight of (M = 1800 mg, max = 2400 mg) and a much wider amplitude of variation in the length (17.9–22.6 vs. 14.3–18.2 mm) of the fruit. The largest leaves were in the genotypes G-08 and G-01, and the smallest – in the genotype G-02. The cultivar Etude did not differ so much by the mean leaf morphometric indices and number of veins, but it demonstrated one of the broadest leaf blades (51.5 mm).
 Conclusions. The data obtained in this study is important for the commercial use of C. officinalis and the cultivar Etude as food and medicinal plant, as well as for breeding in climatic conditions of Ukraine and analysis of hybridization features in the genus Cornus in general.

Improving yield and fruit quality traits in sweet passion fruit: Evidence for genotype by environment interaction and selection of promising genotypes

Breeding for yield and fruit quality traits in passion fruits is complex due to the polygenic nature of these traits and the existence of genetic correlations among them. Therefore, studies focused on crop management practices and breeding using modern quantitative genetic approaches are still needed, especially for Passiflora alata, an understudied crop, popularly known as the sweet passion fruit. It is highly appreciated for its typical aroma and flavor characteristics. In this study, we aimed to reevaluate 30 genotypes previously selected for fruit quality from a 100 full-sib sweet passion fruit progeny in three environments, with a view to estimating the heritability and genetic correlations, and investigating the GEI and response to selection for nine fruit traits (weight, diameter and length of the fruit; thickness and weight of skin; weight and yield of fruit pulp; soluble solids, and yield). Pairwise genetic correlations among the fruit traits showed mostly intermediate to high values, especially those associated with fruit size and shape. Different genotype rankings were obtained regarding the predicted genetic values of weight of skin, thickness of skin and weight of pulp in each environment. Finally, we used a multiplicative selection index to select simultaneously for weight of pulp and against fruit skin thickness and weight. The response to selection was positive for all traits except soluble solids, and the 20% superior (six) genotypes were ranked. Based on the assumption that incompatibility mechanisms exist in P. alata, the selected genotypes were intercrossed in a complete diallel mating scheme. It is worth noting that all genotypes produced fruits, which is essential to guarantee yields in commercial orchards.

СЕЛЕКЦИЯ ЛЮЦЕРНЫ ДЛЯ ПОЧВЕННО-КЛИМАТИЧЕСКИХ УСЛОВИЙ ПРЕДГОРНОЙ ЗОНЫ СЕВЕРНОГО КАВКАЗА

Alfalfa belongs to the legume family and has the ability to accumulate to a greater or lesser extent nutritious nitrogenous substances due to the vital activity of nodule bacteria that settle on its roots. This is a productive and high-protein fodder crop. The inherent high plasticity allows it to adapt to a variety of conditions of existence, so it is distributed almost everywhere. Alfalfa increases soil fertility as a result of nitrogen accumulation. The accumulation of organic matter is of great importance in improving the physical and chemical properties of the soil. Alfalfa has a lot of lysine, and in terms of the content of essential amino acids, it surpasses corn, sorghum, soy, barley and a number of other crops. In recent years, in the North Ossetia-Alania, alfalfa sown areas are expanding, seed demand is growing, but their production remains low. This is due to the lack of adaptive, highly productive varieties of alfalfa resistant to diseases, lodging, and insufficiently studied several issues of the technology of cultivating it for seeds. The aim of the research is to create alfalfa varieties that are resistant to biotic and abiotic stress factors of the environment for cultivation in the North Caucasus based on a targeted selection of promising genotypes. As a result of three years of research, it was found that the alfalfa varieties Senegibridnaya and Kizlyarskaya surpassed other varieties by 5–7% in yield of green mass and foliage. Among the tested alfalfa varieties, Kizlyarskaya cultivar had a higher productivity, in which the yield indicators of green mass, dry matter, and mass of 1000 pcs were most successfully combined. seed. In the perspective of our research, the distinguished varieties will be used to form new varieties of alfalfa.

Heritability, genetic gain and detection of gene action in hexaploid wheat for yield and its related attributes

Selection of promising genotypes from a diverse genetic pool and their utilization for hybridization is an important strategy for wheat crop improvement. The data from ten parents and their F1 progenies using line × tester mating scheme were analyzed to assess the effects of combining ability for yield and its cognate characters using randomized complete block design with three replications. Data were taken for grain yield and its associated characters like plant height, peduncle and spike length, flag leaf area, per plant tillers, spikelets spike−1, grains spike−1, spike density, thousand-grain weight and grain yield plant−1. Analysis of variance was used to statistically analyze the data. Line × tester analysis was used to find out association among traits and to estimate the effects of GCA and SCA. Highly significant differences were found among parents (lines, testers) and their F1 hybrids for all the parameters under study. Among parents, Line 9796 and tester 107 manifested as best general combiners and exhibited significant GCA effects for almost all the mentioned traits. In the case of F1 hybrids, 9793 × 118 and Punjab-2011 × 108 were recognized as best specific combiners exhibiting significant SCA effects. A higher value of SCA variance than the variance of GCA revealed the preponderance of non-additive genetic action. The degree of dominance revealed the involvement of both type of gene action for the traits under investigation. The deviations among total variation were mainly due to genotypes. Most of the yield associated traits were highly heritable with more than 80% heritability. These findings were confirmed by genetic gain. Thus, potential homozygous lines can be selected from transgressive segregants to improve yield and these crosses will be beneficial for commercial exploitation to heterosis.

An assessment of genetic variability for drought tolerance in rice

The genetic variability for yield and yield contributing traits were studied in forty genotypes of rice under moisture-stress (rainfed) and moisture non-stress (irrigated) conditions. The results revealed highly significant differences among the genotypes for all the characters studied. This indicated the ample scope for selection of promising genotypes from the present set of genotypes for yield improvement. The high estimates of GCV and PCV coupled with high heritability and expected genetic advance for yield and important yield contributing traits showed their importance in selection for improving rice yield. The correlation study revealed that grain yield per plant had strong positive associations with effective panicle bearing tillers, days to 50% flowering, days to maturity, panicle weight, filled grains per panicle, total grains per panicle and length of main panicle. This indicated that grain yield of rice can be improved under both the environments having higher per se performances for the above traits. The genotypes such as HUR 105, NDR 359, Swarna were found to be best for yield and yield contributing traits. However, based on the different drought parameters, the varieties such as HUR105, HUR 4–3 and IET-20556 has been identified as drought tolerant which might be utilised in future breeding programmes.

Selection of promising genotypes of lentil (Lens culinaris Medik.) by deciphering genetic diversity and trait association

A panel of fifty diverse genotypes of lentil were evaluated to assess the genetic diversity for 11 morpho-physiological attributes. The results revealed wide range of variability among the genotypes for the examined characteristics. The mean performance demonstrated that the best genotype for more than one trait viz., plot yield, yield/plant, Leaf Area Index (LAI), Crop Growth Rate (CGR), biomass and plant height was LL1384. Traits association approximation witnessed a positive and significant relationship of seed yield with most of the studied traits. Cluster analysis distributed genotypes into seven distinct clusters. Cluster III happened to be the largest comprising of 20 genotypes, followed by Cluster VII comprising of 9 genotypes. The maximum inter-cluster distance was perceived between clusters II and IV which suggests the possibility of high heterotic effect if cross will be made between the individuals of these clusters. The principal component analysis developed 11 Eigen vectors and, of these three principal components had explained about 82.50% of variations. The characters that had the highest weight in component first were plot yield, yield/plant, pods/plant, CGR, biomass/plant, LAI and plant height, which explained 57.03% of the total variance. The biplot results were in accordance with correlation estimation, indicating that indirect selection based on component traits would help in improving the seed yield in lentil. Hybridization among genetically diverse genotypes of different clusters would be helpful in broadening the genetic base as well as in the creation of desirable recombinants for developing new improved lentil varieties.

Seedling emergence and yield performance of wheat cultivars depending on seed vigor and sowing density

Abstract: The use of high quality seeds, the appropriate management practices and the selection of promising genotypes are strategies to exploit the wheat yield potential. Thus, the goal of this study was to evaluate the effect of the vigor level of wheat seeds submitted to different sowing densities on seedling emergence, tillering and yield performance culture. The experiments were conducted in Londrina and Ponta Grossa, Paraná state, Brazil, with a completely randomized block design, in a 2x2x2 factorial scheme, with four replications. Two levels of seed vigor (high and low), two sowing densities (200 and 400 viable seeds per m2) and two wheat cultivars (BRS Sabiá and CD 150) were evaluated. The conducted tests were: seedling emergence, number of tillers, yield components, grain yield and apparent harvest index. The use of high vigor seeds helps the establishment of the plant stand and yield performance in both locations. The 400 seeds per m2 seedling density results in a lower number of tillers per plant in both locations. BRS Sabiá, in Ponta Grossa, has the highest grain yield.

Characterization of the Fruit Pulp of Camu-Camu (Myrciaria dubia) of Seven Different Genotypes and Their Rankings Using Statistical Methods PCA and HCA

Due to the economic potential of camu-camu, considering its high concentration of vitamin C, the aim of this work was to evaluate the quality and genetic variability seven accessions of camu-camu conserved in genebank (BAG) of Embrapa Amazonia Oriental, in the state of Para, Amazon region, Brazil. The fruits of camucamuzeiro were analyzed for physicochemical characterization (standard methodologies) and mineral composition. The data were subjected to multivariate statistical analysis, using the techniques of cluster analysis and principal component analysis. The formation of different groups for each genotype, which shows the genetic variability and the dissimilarity of the genotypes in the species data, may be used to guide the selection of promising genotypes to enrich the programs of genetic improvement of the camucamuzeiro. Ascorbic acid showed levels above 1000 mg 100 g-1, however, genotypes 4, 1 and 2 show the highest potential and the most promising nutritional capacity, but genotype 4 showed good characteristics for the moisture, acidity, carbohydrates, Cu and Zn and differs totally from others about the total soluble solids (TSS) and flavon-3-ol, features that make it the most promising genotype. It was possible to separate the seven different genotypes using multivariate analysis (hierarchical cluster analysis-HCA and principal component analysis-PCA).

Genetic Divergence Among Gerbera spp. Genotypes Based on Morphological Traits

Gerbera is one of the most important ornamental flowers marketed worldwide. Information on the genetic variability of this species represents an important resource for improvement programs that rely on the selection of promising genotypes. The aim of the present study was to assess and characterize the genetic divergence among 32 gerbera accessions based on morphological traits by means of multivariate analysis. A total of 21 traits, nine quantitative and 12 qualitative, were analyzed using clustering analysis and the principal component method. Although the quantitative and qualitative traits were analyzed separately, joint analysis allowed for a more reliable interpretation of the genetic variability and also permitted the identification of wide dissimilarity among the investigated accessions. With regard to the quantitative traits, four main groups were observed, which was in partial agreement with the result of the analysis of canonical variables. The qualitative trait analysis, on the other hand, resulted in the formation of five groups. The traits that contributed most significantly to variability in gerbera were total width of the trans florets set and number of flowers. The data obtained in the present study may be applied directly to improve the design of controlled crosses between gerbera accessions and to better explore the hybrid effect in the process of genetic improvement in this species.

Next generation of elevated [CO2] experiments with crops: a critical investment for feeding the future world

A rising global population and demand for protein-rich diets are increasing pressure to maximize agricultural productivity. Rising atmospheric [CO(2)] is altering global temperature and precipitation patterns, which challenges agricultural productivity. While rising [CO(2)] provides a unique opportunity to increase the productivity of C(3) crops, average yield stimulation observed to date is well below potential gains. Thus, there is room for improving productivity. However, only a fraction of available germplasm of crops has been tested for CO(2) responsiveness. Yield is a complex phenotypic trait determined by the interactions of a genotype with the environment. Selection of promising genotypes and characterization of response mechanisms will only be effective if crop improvement and systems biology approaches are closely linked to production environments, that is, on the farm within major growing regions. Free air CO(2) enrichment (FACE) experiments can provide the platform upon which to conduct genetic screening and elucidate the inheritance and mechanisms that underlie genotypic differences in productivity under elevated [CO(2)]. We propose a new generation of large-scale, low-cost per unit area FACE experiments to identify the most CO(2)-responsive genotypes and provide starting lines for future breeding programmes. This is necessary if we are to realize the potential for yield gains in the future.

Fruit characterization of sugar apple genotypes in Presidente Dutra, Bahia

To identify promising genotypes for commercial cultivations and studies of genetic improvement with sugar apple, eight fruits each of 30 genotypes of the species were charactyerized by: length and fruit diameter, fruit mass, pulp mass, seed mass, rind mass and receptacle mass, pulp yield, number of seeds, thickness of the rind, pH, total soluble solids (TSS), total titratable acidity (TTA), vitamin C, TSS/TTA ratio, moisture, ash content, total, reducing and non-reducing sugars. Results were evaluated by descriptive statistics (mean, standard deviations and coefficient of variation) and statistical multivariate analysis, by grouping techniques and main component analysis. The genotypes were clustered in 10 gentically divergent groups, which allowed the selection of promising genotypes. The highly variable traits fruit, pulp, and rind mass and number of seeds contribute to the differentiation of the evaluated genotypes

Fuelwood production potential of six Prosopis species on an alkaline soil site

The biomass potential of six species of Prosopis was evaluated on highly alkaline soil site. Prosopis alba I was found to have the fastest growth rate and highest above-ground biomass production. P. juliflora ranked next. P. cineraria showed high plant establishment but relatively slow growth. The performance of P. glandulosa was poor on such sites. The high fuelwood value index and rapid growth rate of P. juliflora and P. alba makes them suitable for short-rotation fuelwood forestry programmes on waste-lands. Selection of promising genotypes is suggested as a means of improvement in yields.

SELECTION OF SPRING TRITICALE BREEDING LINES IN SP-2 UNDER THE MIDDLE AMUR REGION STRESS CONDITIONS

An urgent task of breeding work is the creation of new high-yielding varieties of spring triticale, adapted to the conditions of the Middle Amur region. The object of research is 160 breeding lines of spring triticale (Ukro x DalGAU 1; Ukro x Primorskaya 108; Ukro x Lana; Ukro x Erythrospermum). As a result of the research, a significant influence of weather factors of the environment on the realization of the potential productivity of breeding lines of triticale in SP-2 was established, the share of the contribution "environment" was 77 %. Under stressful growing conditions, two early ripening varieties of triticale were identified – 128 (Ukro x Primorskaya 108) and 219 (Ukro x Erythrospermum). Numbers 104 (Ukro x Lana), 205 (Ukro x Lana), 206 (Ukro x Lana) were characterized by high resistance to Fusarium spike. The average yield of the selection lines of triticale in SP-2 was 2.8 t/ha, in the standard varieties of triticale Ukro and wheat Khabarovchanka – 2.4 t/ha. For the effective selection of promising genotypes, the differentiation of breeding lines of spring triticale by yield and its structural elements was carried out using the methods of multivariate statistical analysis (cluster analysis). As a result of the research, the studied triticale lines were grouped into 4 clusters according to the criterion of the greatest similarity: cluster I – 33 samples, cluster II and III – 24 nomers, cluster IV – 79 selection lines. Samples of the second cluster (Ukro x DalGAU 1 – 102, 116, 115, 119, 120, 103, 104, 106, 109, 117; Ukro x Lana – 178, 181, 185, 188, 182; Ukro x Primorskaya 108 – 122, 123; Ukro x Erythrospermum – 258, 218, 212, 237, 223, 224, 230) are distinguished by the maximum values ​​of the main economically valuable indicators of productivity in the complex hydrothermal conditions of the Middle Amur region.