Euphytica

Ngwepe, Richard Mantlo; Shimelis, Hussein; Mashilo, Jacob

doi: 10.1007/s10681-023-03246-6pmid: N/A

Yield gains in crop plants, such as citron watermelon can be realised through combining ability tests and hybrid breeding. The objective of the study was to determine the combining ability and hybrid performance of citron watermelon genotypes for agronomic traits. Five contrasting and relatively high-yielding citron watermelon genotypes were crossed in a 5 × 5 half-diallel mating design and 10 F1 hybrids were developed. The 15 families (five parents and 10 F1 hybrids) were evaluated across two environments using a randomized complete block design with three replications. Data was collected on various agronomic traits and subjected to analysis of variance (ANOVA) and combining ability analysis. Significant (P < 0.001) genotype × environment interaction effects were observed for most assessed traits. General combining ability (GCA) and specific combining ability (SCA) effects were significant (P < 0.001) for most traits. Environment × GCA was non-significant, whereas Environment × SCA effects were significant (P < 0.001) for most traits. The ratios of GCA/SCA variances were less than unity for most traits, indicating non-additive gene action of the traits. Broad-sense heritability varied from low to moderate, implying variable selection response of the assessed traits among the F1 hybrids. The parental genotypes WWM16 with positive GCA effects for fruit and seed yields and WWM66, with positive GCA effects for the number of seeds per fruit and seed yield, were identified for hybrid breeding. The following F1 hybrids: WWM04 × WWM16, WWWM03 × WWM66 and WWM16 × WWM50 with positive SCA effects on total fruit yield per plant and marketable fruit yield per plant, and WWM04 × WWM50, WWM03 × WWM16 and WWM03 × WWM66 with positive SCA effects for number of seeds per fruit and total seed yield were identified. The study identified novel and best-performing F1 hybrids of citron watermelon for economic traits and are recommended for multi-environmental evaluations, variety registration and commercialization.

Degu, Hewan Demissie; Semahegn, Ayalnesh; Sato, Kazuhiro

doi: 10.1007/s10681-023-03241-xpmid: N/A

PurposeAcid-tolerant barley has a one-kbp insertion at the 5’ untranslated region of HvAACT1. Marker-assisted breeding based on the one-kbp at the 5’ UTR enhances acid tolerance in barley. Under acidic growing conditions, a two-year experiment was conducted to determine the variability and interrelationships of 12 quantitative traits that regulate yield in the F2 and F3 populations of the cross between E232 and Murasakimochi and their resprocal cross. A higher phenotypic coefficient of variation indicated a prevalence of adequate variability for the measured traits. The kernels per spike and plant ranged from 11–95 seeds per spike and 0–668, respectively. Plant height and shoot length ranged from 51 to 155 cm and 2.5 to 17 cm, respectively. Thousand seed weights and yield per plant ranged from 0–73 g to 0–36 g/plant, respectively. The peduncle length, peduncle extrusion length, flag leaf width, and flag leaf length showed similar patterns of variation: 14 to 51 cm, 3.4 to 30.7 cm, 4.1-\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$-$$\end{document}70.5 cm, and 0.3-\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$-$$\end{document}0.6 cm, respectively. A positive correlation was observed for all traits. There was positive skewness with the number of tillers, yield per plant, kernels per plant, and thousand seed weights. Kernel per spike, shoot length, flag leaf width, and plant height showed negative skewness, which indicates duplicate epistasis of dominant genes in trait inheritance. The biplot analysis showed that the mean performance of all measured traits was high between genotypes with the one-kbp insertion of the HvAACT1 gene. The lines without insertion have the lowest mean value.Marker-assisted selection accelerates the selection of barley lines with acid tolerance one-kbp insertion.

Verbyla, Arūnas

doi: 10.1007/s10681-023-03248-4pmid: N/A

Two-stage analysis methods are often used in multi-environment trials (MET) for plant variety selection, when a single-stage approach is not feasible or too time consuming. In any two-stage analysis, the estimated effects taken to stage two must be unbiased for the effects of interest, and this means using best linear unbiased estimates based on a model with fixed genetic effects. The error (or weights) associated with the estimates must also be taken to stage two. These weights are functions of unknown variance parameters that need to be estimated at stage one. These parameters may be better estimated if genetic effects are taken as random, but resulting predicted genetic effects are biased. The bias can be removed by so-called de-regression in animal sciences. The proper weights involve a block diagonal matrix with blocks corresponding to environments, whereas diagonal weights were originally proposed in animal sciences. Two MET experiments, one fully replicated and one with partial replication of varieties, were used to compare one-stage and two-stage approaches. The results were similar, but using a full weight matrix for two-stage methods was superior to using diagonal weights. A small simulation study for trials with partial replication showed that fitting random genetic effects, de-regressing, and using a full weight matrix, was very similar to a one-stage analysis, and was superior to starting with fixed genetic effects at stage one. The use of diagonal weights was found to be very poor.

Bettinelli, Paola; Nicolini, Daniela; Giovannini, Oscar; Stefanini, Marco; Hausmann, Ludger; Vezzulli, Silvia

doi: 10.1007/s10681-023-03235-9pmid: N/A

Crop improvement by means of traditional or molecular breeding is a key strategy to accomplish the European Green Deal target of reducing pesticides by 50% by 2030. Regarding viticulture, this is exacerbated by the massive use of chemicals to control pathogen infections. Black rot is an emergent disease caused by the ascomycete Phyllosticta ampelicida, and its destructiveness is alarming vine growers. Implementing and improving effective phenotyping strategies are fundamental preliminary steps to breed disease resistant varieties and this work suggests good practices adopted for this purpose. Primarily, the pedigree of black rot resistance donors was reconstructed based on the collection of phenotypic historical data, highlighting unexplored sources of black rot resistance. Strains used for artificial infections were isolated, genetically characterized and mixed to avoid race-specific resistance selection. A new inoculation protocol based on the use of leaf mature lesions was developed. Ex vivo inoculation on detached leaves was effective for the evaluation of conidia germination and hyphal growth, but not for disease progression. Finally, the pedigree was used for the identification of 23 genotypes to be tested. Two breeding selections (NY39 and NY24) resulted symptomless in all assessments and a third one (F25P52) also showed very high resistance, although with a greater variability. Other two genotypes (F12P19 and ‘Charvir’) fell within the medium resistance category, making them good candidates in a regime of well-timed preventive treatments. In conclusion, this work was effective to a comprehensive parental line characterization and preparatory towards grapevine breeding programs for black rot resistance.

Katsura, Naoyuki; Itoh, Kanna; Matsuhira, Hiroaki; Kuroda, Yosuke; Kubo, Tomohiko; Kitazaki, Kazuyoshi

doi: 10.1007/s10681-023-03244-8pmid: N/A

Cytoplasmic male sterility (CMS) is a mitochondrion-encoded trait specifically affecting anthers. Several male sterility-inducing mitochondrial types are known, many of which affect the development of anther tapetum cells, but no sound explanation for this tissue's vulnerability has been proposed. Insights into the cause of CMS can be obtained by the detailed phenotypic comparison of different male sterility-inducing mitochondrial types of the same plant species. In pursuit of this objective, we conducted an investigation into anther development in two sugar beet CMS lines. We compared an Owen type CMS line used for hybrid breeding with the G type CMS line derived from wild beet. Both CMS lines have the same nuclear background. The tapetum of the G CMS line exhibited hypertrophy in the microspore stage, as reported previously in Owen CMS lines. Ultrastructural analysis revealed mitochondrial abnormalities, including low electron density and aberrant cristae appearing in the tapetum after meiosis in both lines. The Owen CMS line lacked Ubisch bodies and had poorly developed bacula and tecta in the pollen cell walls, whereas the G CMS line retained these features, but the pollen wall was highly deformed. Ultimately, microspores and the tapetum degenerated in both lines, and the male sterile phenotypes were eventually very similar. Although it had been hypothesized that mitochondrial activation was associated with CMS expression, mitochondria in the root apical meristem appeared normal in beet roots with G- and Owen type mitochondria. We propose that CMS expression includes at least two mechanisms: one triggers abnormal mitochondrial generation, and the other affects the type of developmental abnormality.

de Andrade Dutra Filho, João; Porto, Andrea Chaves Fiuza; Alvino, Francisco Cássio Gomes; de Luna, Rômulo Gil; dos Santos Souza, Anielson; Souto, Lauter Silva; de Castro Silva, Marcelo Cleon; Gomes-Silva, Frank; Dantas, Jussara Silva; Souto, Jacob Silva; Neder, Diogo Gonçalves; Júnior, Tercilio Calsa

Yadav, Sunaina; Singh, S. P.; Singhal, Tripti; Sankar, S. Mukesh; Bhargavi, H. A.; Aavula, Naveen; Satyavathi, C. Tara

doi: 10.1007/s10681-023-03245-7pmid: N/A

Grain color in pearl millet is a combination of the color and thickness of the pericarp, particularly the mesocarp, and the color and vitreosity of the endosperm. Pearl millet has a thin pericarp which allows endosperm color and texture to appear through pericarp. Segregation analysis involving F1, F2, and BC1 populations from six crosses WGI 100 × ICMB 13222, HFeIT 17/2 × PPMI 1229, ICMB 13222 × PPMI 1229, HFeIT 17/2 × WGI 100, ICFD 14-R-61 × WGI 100 and ICFD 14-R-61 × PPMI 1229 revealed that single pair of major genes governs cream grain color in pearl millet. Cream grain color was found to be dominant over grey grain color. Two DNA pools were established from the homozygote cream and grey grain color plants for bulked segregant analysis. Among the 313 pairs of microsatellite primers used in the present study, three markers showed polymorphism in DNA pools, parents, F1and F2 populations. Molecular mapping and validation revealed that the gene controlling cream grain color is present on linkage group 2 and flanked by markers Xpsmp 2089 and Xipes 0218 at a distance of approximately 16.9 cM and 17.9 cM, respectively. This work is the first report on the molecular mapping of the gene that controls the color of cream grains in pearl millet.

Costa, Cristina dos Santos Ribeiro; Costa, Antonio Elton da Silva; Neto, Francisco Pinheiro Lima; de Lima, Maria Auxiliadora Coêlho; Martins, Luiza Suely Semen; Musser, Rosimar dos Santos

doi: 10.1007/s10681-023-03249-3pmid: N/A

Mango is a tropical fruit of significant economic, social, and nutritional importance. However, the low diversity of commercial mango orchards in Brazil highlights the need to broaden the genetic base of this crop. From this perspective, this study aimed to select mango genotypes for cultivation under semi-arid conditions using the mixed model methodology: restricted maximum likelihood/best linear unbiased prediction (REML/BLUP). Two hundred and ninty-two genotypes originated from the crossing of seven cultivars used as female parent ('Coquinho', 'Espada', 'Haden', 'Keitt', 'Winter', 'Palmer', and 'Van Dyke') and 'Tommy Atkins' as male parent were evaluated over two crop seasons using fifteen traits related to fruit quality. The statistical analyses were performed with the software Selegen. The repeatability coefficient estimates (r) ranged from 0.06 to 0.97, and were considered high for most variables. The selective accuracy predicted by REML for the evaluated parameters ranged from 0.25 to 0.98, revealing a good degree of confidence in the inferences. With the application of a selection intensity of 30% it was possible to obtain genetic gain (%) for all evaluated traits. Twelve genotypes were selected as the most promising using the minimum selection indices proposed in this study, showing higher mean values for all evaluated traits. These genotypes can be selected for new stages of the mango breeding program in the Brazilian semi-arid region.

Orcheski, Benjamin; Hedderley, Duncan; Hunt, Martin; Rowan, Daryl; Volz, Richard

doi: 10.1007/s10681-023-03239-5pmid: N/A

Flavor is a major component of the apple eating experience, along with taste, texture and appearance. Apples produce a wide array of volatile organic compounds that impart particular flavors. Cultivars producing increased or novel flavors may have more desirability for consumers and help to differentiate the fruit. Efficiently breeding more flavorful apples requires understanding the volatiles present in apple germplasm and their potential sensory impact. As an initial step towards the development of more flavorful apple cultivars, a New Zealand collection of germplasm was surveyed, and seventy-three volatiles were identified as being present in at least half the accessions. Substantial differences in the presence and relative abundance of specific volatiles were uncovered across the accessions and could sometimes be linked to an apple’s flavor profile. The large number of volatiles analyzed allowed relationships between and among molecule classes to be established. Esters were found to be the main drivers of volatile differentiation across accessions. Apples tended to produce either ethyl or acetate esters, suggesting there is different genetic control for these two ester types. Additionally, esters generally had larger broad-sense heritabilities, indicating they could be easier targets for modifying apple flavor. This volatile dataset is a valuable resource for apple breeding, and increases the understanding of an important consumer trait.

Ly, Sarath; Lee, Jeong Hwan; Oh, Hyeon Su; Kim, Se Yeong; Choi, Sang Woo; Chung, Jong Il

doi: 10.1007/s10681-023-03240-ypmid: N/A

Soybean [Glycine max (L.) Merr.] is an excellent source of protein for humans, but several allergenic and antinutritional components such as P34, lectin, Kunitz Trypsin Inhibitor (KTI), and 7S α′ subunit proteins exist in the raw mature seed. Genetic elimination of these factors would be the appropriate method to improve soybean food quality. The objective of this research was to develop a new soybean line with a tetra null recessive genotype (titilelecgy1cgy1p34p34) based on Mendelian inheritance. Four germplasms were used to develop the tetra null strain. A total of 322 F2 seeds were obtained from the cross of parent 1 and parent 2. For four proteins of KTI, lectin, 7S α′ subunit and P34, and segregation ratio of 107:30:37:8:35:9:14:3:33:9:14:0:13:3:5:2 was observed (χ2 = 9.41, P = 0.9 ~ 0.5). Two F2 seeds possessing the tetra null genotype (cgy1cgy1titilelep34p34) were selected. Confirmation of the Tetra null genotype (titilelecgy1cgy1p34p34—absence of KTI, lectin, 7S α′ subunit and P34 proteins) was verified on the random F3 seeds of the two lines selected. The seed color for both selection lines was yellow and the hilum color was buff. The seed weights (g/100 seeds) for the two selected lines were 12.2 and 12.0 g. This paper is the first to investigate the genetic segregation ratio and selection of tetra null genotype for four proteins of P34, lectin, KTI and 7S α′ subunit proteins in soybean.