Half-sib Progenies Research Articles

Multi-season-based estimation of genetic diversity, correlation and path analysis in spearmint (Mentha spicata L.) half-sib populations

Spearmint (Mentha spicata L.) is popular for its medicinal benefits and industrial uses, in this study forty-three half-sib progenies were evaluated over three seasons at CSIR-CIMAP, Research Centre Pantnagar to study genetic variability, correlation, path coefficient analysis and Mahalanobis D2 diversity by using five morphological and two biochemical traits. These forty-three half-sib populations were derived from nine commercially existing spearmint varieties through an intra-population improvement method. Results of correlation and path coefficient studies indicated the paramount importance of certain key traits in the selection process. Notably, traits such as herb yield per plot (kg), plant height (cm) and oil content (%) emerged as pivotal, exhibiting positive correlations, high heritability and moderate to high genetic advance. These attributes, therefore need primacy in the selection of superior lines. Furthermore, genotypes OPSP-106, OPSP-92, OPSP-47, OPSP-35 and OPSP-76 showed significant genetic divergence. These accessions hold promise as parent candidates for hybridization experiments aimed at finding transgressive segregants in later generations. Additionally, this study highlighted the presence of specific oil components, such as carvone and limonene, offering insights into potential avenues for targeted breeding efforts. This study provides a holistic view of the genetic makeup of Mentha spicata genotypes, enabling informed decisions in breeding programs. By prioritizing traits and maximizing genetic diversity, the results of this investigation will contribute to the development of improved spearmint varieties with enhanced morphological and biochemical characters, thus advancing the medicinal and industrial applications of spearmint.

Trunk distortion weakens the tree productivity revealed by half-sib progeny determination of Pinus yunnanensis

Twisted trunks are not uncommon in trees, but their effects on tree growth are still unclear. Among coniferous tree species, the phenomenon of trunk distortion is more prominent in Pinus yunnanensis. To expand the germplasm of genetic resources, we selected families with excellent phenotypic traits to provide material for advanced generation breeding. The progeny test containing 93 superior families (3240 trees) was used as the research material. Phenotypic measurements and estimated genetic parameters (family heritability, realistic gain and genetic gain) were performed at 9, 15, and 18 years of age, respectively. The genetic evaluation yielded the following results (1) The intra-family variance component of plant height (PH) was greater than that of the inter-family, while the inter-family variance components of other traits (diameter at breast height (DBH), crown diameter (CD), height under branches (HUB), degree of stem-straightness (DS)) were greater than that of the intra-family, indicating that there was abundant variation among families and potential for selection. (2) At half rotation period (18 years old), there was a significant correlation among the traits. The proportion of trees with twisted trunks (level 1–3 straightness) reached 48%. The DS significantly affected growth traits, among which PH and DBH were the most affected. The volume loss rate caused by twisted trunk was 18.06-56.75%, implying that trunk distortion could not be completely eliminated after an artificial selection. (3) The influence of tree shape, crown width, and trunk on volume increased, and the early-late correlation between PH, DBH and volume was extremely significant. The range of phenotypic coefficient of variation, genetic variation coefficient and family heritability of growth traits (PH, DBH, and volume) were 44.29-127.13%, 22.88-60.87%, and 0.79–0.83, respectively. (4) A total of 21 superior families were selected by the method of membership function combined with independent selection. Compared with the mid-term selection (18 years old), the accuracy of early selection (9 years old) reached 77.5%. The selected families’ genetic gain and realistic gain range were 5.79-19.82% and 7.12-24.27%, respectively. This study can provide some useful reference for the breeding of coniferous species.

Growth and productivity of half-sibs progenies of selected Robinia pseudoacacia L. clones in the region of Ruse.

An assessment was made on the main growth and productivity indicators in half-sibs progeny planta-tions of 18 Robinia pseudoacacia L. clones in the region of Ruse, on (М-I-2 D1 (13)) site, on rich, dry and compacted (Haplic luvisols) grey forest soil, at planting scheme 3.0х1,5 m. The differences in the main inventory indicators, defining the growth and productivity of the progenies of 18 black locust clones, confirm good qualities of the progenies of the Bulgarian clones Pordim-10, Pordim-13, Obretenik-1, Obretenik-6 and Ryahovo-1 and of the Hungarian clones Szajki and Nyirségi. This should be taken into account in the selection of material for establishment of industrial plantations and plantations for bio-mass production, as well as in the choice and performance of tending activities. 

The Effect of Genome Parametrization and SNP Marker Subsetting on Genomic Selection in Autotetraploid Alfalfa.

Alfalfa, the most economically important forage legume worldwide, features modest genetic progress due to long selection cycles and the extent of the non-additive genetic variance associated with its autotetraploid genome. To improve the efficiency of genomic selection in alfalfa, we explored the effects of genome parametrization (as tetraploid and diploid dosages, plus allele ratios) and SNP marker subsetting (all available SNPs, only genic regions, and only non-genic regions) on genomic regressions, together with various levels of filtering on reading depth and missing rates. We used genotyping by sequencing-generated data and focused on traits of different genetic complexity, i.e., dry biomass yield in moisture-favorable (FE) and drought stress (SE) environments, leaf size, and the onset of flowering, which were assessed in 143 genotyped plants from a genetically broad European reference population and their phenotyped half-sib progenies. On average, the allele ratio improved the predictive ability compared with other genome parametrizations (+7.9% vs. tetraploid dosage, +12.6% vs. diploid dosage), while using all the SNPs offered an advantage compared with any specific SNP subsetting (+3.7% vs. genic regions, +7.6% vs. non-genic regions). However, when focusing on specific traits, different combinations of genome parametrization and subsetting achieved better performances. We also released Legpipe2, an SNP calling pipeline tailored for reduced representation (GBS, RAD) in medium-sized genotyping experiments.

Biometrics and screening of kale (Brassica oleracea var. acephala) half-sib progenies obtained by recurrent selection in Brazil

Biometrics and screening of kale (Brassica oleracea var. acephala) half-sib progenies obtained by recurrent selection in Brazil

Assessment of the adaptability, growth and yield parameters of half-sib progenies of Melia composita Benth. in northwestern India

Assessment of the adaptability, growth and yield parameters of half-sib progenies of Melia composita Benth. in northwestern India

Chemical composition and antiprotozoal potential of essential oil from half-sib progenies of Varronia curassavica Jacq.

Chemical composition and antiprotozoal potential of essential oil from half-sib progenies of Varronia curassavica Jacq.

Correlation study on morphological and biomass traits in half-sib progenies of Neolamarckia cadamba

Correlation study on morphological and biomass traits in half-sib progenies of Neolamarckia cadamba

Genetic control of growth and wood traits in Eucalyptus camaldulensis × E. urophylla and reciprocal hybrids

Eucalyptus camaldulensis (Ec) × E. urophylla (Eu) and reciprocal hybrid crosses were evaluated for growth and wood traits at four years at West Godavari Dt, Andhra Pradesh State located in Southern India, in relation to full and half sib progenies of pure E. camaldulensis maternal parents. Interspecific hybrid progenies had 16.6% higher average growth and 8% lower average wood basic density than pure species progeny. The interspecific hybrid progenies fibre properties viz., fibre length, fibre width, lumen diameter and fibre wall thickness were comparably higher than pure species progeny and check clones. The Ec × Eu crosses had comparable growth and wood basic density as the reciprocal hybrid progeny, but fibre length was 3.4% higher than the Eu × Ec hybrids, the values being statistically significant at p<.001 level. Analysis of variance of data was done using the 20th Edition of Genstat software (VSNi). Growth and fibre traits showed a positive relation but wood basic density showed a negative correlation (r = -0.94). There was a positive correspondence between the General Combining Ability (GCA) of pure E. camaldulensis maternal parents and their General Hybridizing Ability (GHA) for growth. The study showed that parents of Ec and Eu could be used to improve the growth and fibre traits in interspecific hybrids.

Correlation Studies for Morphological and Biomass Traits in Half-sib Progenies of Peltophorum pterocarpum

The current research was conducted on twenty plus trees of Peltophorum pterocarpum from different locations in Bihar to study the association among different morphological and biomass traits. It was found that PPT12 (Rajgir Park) and PPT4 (Muraura, Nalanda) performed better for germination metrics under open field and greenhouse conditions, respectively. PPT6 (Nari, Nalanda) and PPT13 (Sathopur, Nalanda) outperformed all other superior tree progenies in terms of morphological and biomass attributes in green house and open field conditions, respectively. The phenotypic coefficient of variability was greater than the genotypic coefficient of variability for all morphological and biomass variables tested under green house and field conditions, showing that the environment played a greater role. Germination value heritability was found to be high in both environments. High heritability with high genetic advance was associated with shoot length in greenhouse condition, indicating additive gene action. Under greenhouse conditions, the phenotypic correlation coefficients among the seedling parameters evaluated varied from a non-significant 0.211 (P=0.01) between shoot root ratio and root dry weight and between shoot length and collar diameter to a very significant 0.967 (P=0.01).Accessions showing higher values for one or the other attributes could be selected as parents for further improvement.

Comparing modeling methods of genomic prediction for growth traits of a tropical timber species, Shorea macrophylla.

Shorea macrophylla is a commercially important tropical tree species grown for timber and oil. It is amenable to plantation forestry due to its fast initial growth. Genomic selection (GS) has been used in tree breeding studies to shorten long breeding cycles but has not previously been applied to S. macrophylla. To build genomic prediction models for GS, leaves and growth trait data were collected from a half-sib progeny population of S. macrophylla in Sari Bumi Kusuma forest concession, central Kalimantan, Indonesia. 18037 SNP markers were identified in two ddRAD-seq libraries. Genomic prediction models based on these SNPs were then generated for diameter at breast height and total height in the 7th year from planting (D7 and H7). These traits were chosen because of their relatively high narrow-sense genomic heritability and because seven years was considered long enough to assess initial growth. Genomic prediction models were built using 6 methods and their derivatives with the full set of identified SNPs and subsets of 48, 96, and 192 SNPs selected based on the results of a genome-wide association study (GWAS). The GBLUP and RKHS methods gave the highest predictive ability for D7 and H7 with the sets of selected SNPs and showed that D7 has an additive genetic architecture while H7 has an epistatic genetic architecture. LightGBM and CNN1D also achieved high predictive abilities for D7 with 48 and 96 selected SNPs, and for H7 with 96 and 192 selected SNPs, showing that gradient boosting decision trees and deep learning can be useful in genomic prediction. Predictive abilities were higher in H7 when smaller number of SNP subsets selected by GWAS p-value was used, However, D7 showed the contrary tendency, which might have originated from the difference in genetic architecture between primary and secondary growth of the species. This study suggests that GS with GWAS-based SNP selection can be used in breeding for non-cultivated tree species to improve initial growth and reduce genotyping costs for next-generation seedlings.

The growth rate and genetic variability of Scots pine (Pinus sylvestris L.) half-sibs in test crops of Northern Kazakhstan

Scots pine (Pinus sylvestris L.) is a valuable tree species, playing an important role in maintaining the ecological and economic balance not only in Kazakhstan, but also in many countries around the world. The purpose of this study was to assess the growth rate and to identify the genotypes of the half-sib progeny of Scotch pine plus trees in order to further obtain high-quality seeds with valuable genetic traits. A molecular genetic analysis was carried out using six microsatellite and 20 isoenzyme loci on 15 Scots pine half-sib families, represented by two samples of seeds collected in the subsequent harvesting periods (planted in 1986 and 1987), that evaluated the taxonomic characteristics such as tree height and trunk diameter (DBH, measured at 1.3 meters). Families with the highest growth rate in both samples were selected as candidates for the elite group. During the SSR analysis, a decrease in the level of expected heterozygosity (0.2377-0.5362 with an average value of 0.4593) was observed in P. sylvestris L. half-sibs compared to the sample of maternal plus trees (0.5444), with similar results to that of the “founder effect”. At the same time, the level of observed heterozygosity remained sufficiently high (0.3333-0.7037 with an average value of 0.4980 and 0.4556, respectively). During the isoenzyme analysis, the level of genetic variability either decreased or was similar to that of the maternal trees. Rare and unique alleles were found in seed samples of the analysed tree families. In general, this research showed that a comprehensive evaluation combining both traditional breeding methods (genetic assessment of progeny in the course of growth) and molecular genetic analysis is required for the selection of elite trees.

Cinco ciclos de seleção recorrente intrapopulacional em progênies de meioirmãos de milho fresco

ABSTRACT Fresh corn is a highly appreciated vegetable in Brazil; this crop has high added value and profitability when compared to dry corn. Despite the consumer market demand for quality, cultivars are not launched every crop season and there is a small number of cultivars available to growers. This denotes a need for breeding programs focused on generating information and genotypes that can occupy this market niche. The objective of this work was to evaluate the progress of five cycles of intrapopulation recurrent selection in half-sib progenies of fresh corn, in the southwest region of Goiás. A randomized block experimental design was used, with evaluation of 64 progenies of corn half-sib progenies and selection intensity of 30% per cycle, with three replications, in the 2011-2012, 2013-2014, 2015-2016, 2017-2018, and 2020-2021 summer crop seasons. The half-sib progenies of fresh corn exhibited genetic variability through intrapopulation recurrent selection in the different selection cycles, which is still promising for further selections after five cycles, with evaluation of 64 progenies per cycle. The base population from crossings between hybrids for tropical and temperate climates showed to be promising for increasing the genetic base of fresh corn populations, with satisfactory gains over the five cycles, presenting mean heritability between the cycles of approximately 78.9% for relative chlorophyll index, 62.2% for plant height, 75.1% for ear insertion height, 70% for ear diameter, 56.6% for ear length, 71.4% for unhusked ear yield, and 71% for marketable ear yield.

Phenotyping floral traits and essential oil profiling revealed considerable variations in clonal selections of damask rose (Rosa damascena Mill.)

Damask rose (Rosa damascena Mill.) is a high-value aromatic plant species belonging to the family Rosaceae. It is being cultivated throughout the world for rose essential oil production. Besides its higher demand in the aromatic and cosmetic industry, the essential oil obtained has many pharmacological and cytotoxic activities. The primary concern of growers with the available varieties of damask rose is short flowering duration, low essential oil content and unstable yield. Thus, there is a requirement for developing new stable varieties with higher flower yield and essential oil content. The present study evaluated the variations in the flower yield parameters, essential oil content, and essential oil compounds in different clonal selections of damask rose. These clonal selections have been developed through a half-sib progeny approach from commercially available varieties 'Jwala' and 'Himroz.' The fresh flower yield varied from 629.57 to 965.7 g per plant, while the essential oil content ranged from 0.030–0.045% among the clonal selections. The essential oil profiling via gas chromatography–mass spectrometry revealed significant variations in the essential oil compounds. Acyclic monoterpene alcohols citronellol (20.35–44.75%) and geraniol (15.63–27.76%) were highest, followed by long-chain hydrocarbons, i.e., nonadecane (13.02–28.78%). The clonal selection CSIR-IHBT-RD-04 was unique in terms of the highest citronellol content (44.75%) and citronellol/geraniol (C/G) ratio of 1.93%. This selection has the potential use as a parental line in future genetic improvement programs of damask rose to achieve higher yield and better quality of rose essential oil.

Exceptionally high genetic variance of the doubled haploid (DH) population of poplar

Doubled haploid (DH) plants have been widely used for breeding and biological research in crops. Populus spp. have been used as model woody plant species for biological research. However, the induction of DH poplar plants is onerous, and limited biological or breeding work has been carried out on DH individuals or populations. In this study, we provide an effective protocol for poplar haploid induction based on an anther culture method. A total of 96 whole DH plant lines were obtained using an F1 hybrid of Populus simonii × P. nigra as a donor tree. The phenotypes of the DH population showed exceptionally high variance when compared to those of half-sib progeny of the donor tree. Each DH line displayed distinct features compared to those of the other DH lines or the donor tree. Additionally, some excellent homozygous lines have the potential to be model plants in genetic and breeding studies.

Genetic Variability and Correlation Estimates for Morpho-Physiological Characteristics in Half Sib Progenies of Toona ciliate

Genetic Variability and Correlation Estimates for Morpho-Physiological Characteristics in Half Sib Progenies of Toona ciliate

Genetic relationships among yearling weight, frame score and fertility traits in Charolais heifers

The objective was to estimate heritability, genetic correlations and expected genetic superiority (EGS) by direct selection, and expected correlated genetic superiority of selected sires for yearling weight (YW), frame score (FS), age at first calving (AFC) and heifer fertility (HF) of Mexican Charolais females. Records were provided by the Charolais-Charbray Herd Book de México. Estimates of (co)variance components were estimated applying a four-trait animal model that included direct genetic effect, contemporary group, and the linear and quadratic effect of dam age, except for AFC. Heritability estimates were 0.18, 0.13, 0.15, and 0.13 for YW, FS, AFC and HF, respectively. Genetic correlations (r2) estimates were 0.60, -0.14, 0.14, -0.24, 0.26 and -0.92 for YW-FS, YW-AFC, YW-HF, FS-AFC, FS-HF and AFCHF, respectively. The EGS with 5 and 500 half-sib progeny per sire was 4.72 and 10.58, 0.10 and 0.26, 23.98 and 57.92, and 0.15 and 0.38 for YW, FS, AFC and HF, respectively. The moderate r2 for YW-FS suggests that direct selection to increase YW would increase FS. The strong r2 for AFCHF indicates that direct selection to decrease AFC would improve HF. The low r2 for YW-AFC and YW-HF indicate direct selection for YW would not alter AFC and HF.

Evaluation and selection in half-sib progenies of Psidium guajava aiming to identify pink pulp with soft seed progeny

Guava (Psidium guajava L) is one of the commercially important fruit crops being cultivated in India. Of late, pink pulp varieties are getting commercial importance due to its consumer preference. However, pink pulp varieties are having higher number of seeds with bold seed size, which limits its wide acceptance. Hence, in the present study it is aimed to identify genotypes with deep pink or red colour pulp with few soft seeds. The study comprises of 48 half-sib progenies from the group of 337 half-sib progenies of guava var. Arka Kiran based on their flowering and fruiting performance. High and moderate level of genotypic and phenotypic coefficient of variances were recorded for fruit weight, fruit yield, plant height, plant girth, fruit length and fruit circumference indicating that the progenies have adequate genetic variability and these traits are suitable for further improvement through selection. From the results of ICP-MS analysis of two best performing genotypes (PG 1–7 and PG 34–1) and its parent Arka Kiran, it is revealed that PG 1–7 and PG 34–1 had higher level of mineral contents when compared to its parent Arka Kiran. The results of the principal component analyses indicated which were the primary traits and are utilized for progeny selection amongst the population. It is inferred that the PC1 and PC2 exhibited better fruit quality and biochemical traits. Molecular diversity analysis of 12 selected progenies using molecular markers inferred that the better performing progeny PG 1–7(B) and the parent Arka Kiran (A) were distinctly placed in the separate clusters, that shows genetic dissimilarity of genotype PG 1–7 from the parent Arka Kiran, which confirms that PG 1–7 is the potential progeny and it could be prioritized for commercial exploitation amongst the progenies studied.

Full-sib progenies show greater genetic diversity than half-sib progenies in sour passion fruit: an approach by ssr markers.

Genetic variability is the most important parameter in plant breeding based on selection. There is a need for morpho-agronomic and molecular characterization of Passiflora species, to exploit their genetic resources more efficiently. No study has yet been carried out to compare half-sib and full-sib families in relation to the magnitude of the genetic variability obtained in them, and then to elucidate the advantages or disadvantages of each one. In the present study, SSR markers were used to evaluate the genetic structure and diversity of half-sib and full-sib progenies of sour passion fruit. Two full-sib progenies (PSA and PSB), and a half-sib progeny (PHS), together with their parents, were genotyped with a set of eight pairs of SSR markers. Discriminant Analysis of Principal Components (DAPC) and Structure software were used to study the genetic structure of the progenies. The results indicate that the half-sib progeny has lower genetic variability, although it has higher allele richness. By the AMOVA most of the genetic variability was found within the progenies. Three groups were clearly observed in the DAPC analysis, while two hypothetical groups (k = 2) were observed in the Bayesian approach. The PSB progeny showed a high genetic mixture between the PSA and PHS progenies. Lower genetic variability is found in half-sib progenies. The results obtained here allow us to suppose that the selection within full-sib progenies will possibly provide better estimates of genetic variance in sour passion fruit breeding programs, since they provide greater genetic diversity.

Genetic analysis and elite tree selection of the main resin components of slash pine.

Pine resin, as a natural material, has been widely used in food, pharmaceutical, and chemical industries. Slash pine (Pinus elliottii Engelm var. elliottii) is the primary tree species for resin tapping due to its high resin yield, low resin crystallization rate, and high turpentine content. Current researches focuse on the targeted improvement of several significant components to meet industrial needs rather than just resin yield. The objective of this study was to examine the genetic variation and correlation of genetic and phenotype for four main resin components (α pinene, β pinene, abietic acid, and levoprimaric acid) of 219 half-sib progenies from 59 families. The results showed that the levopimaric acid had the largest content (mean value = 21.63%), while the β pinene content had the largest variation coefficient (CV = 0.42). The α pinene content has the highest heritability (h2 = 0.67), while levopimaric acid has the lowest heritability (h2 = 0.51). There was a significant negative correlation between α pinene and the other three components and a significant positive correlation between β pinene and the two diterpenes. The family ranking and genetic gain suggested that it is possible to improve the contents of main resin components of slash pine through genetic breeding selection.