This study investigated the combining ability, heterosis and heterotic grouping of maize (Zea mays L.) inbred lines to enhance hybrid performance and productivity. Twenty-four hybrids were developed by crossing eight inbred lines with three testers, and their performance was evaluated for two years at Banaras Hindu University's agricultural research farm. Data on yield and yield-attributing traits were collected from selectively centred competitive plants in each row, avoiding border plants to reduce errors. Biometrical techniques, cluster analysis, and statistical tools were employed to measure general combining ability (GCA), specific combining ability (SCA), and standard heterosis, providing insights into hybrid performance. Analysis of variance revealed significant mean square values for GCA and SCA across most traits studied. Various methods were utilized, including SCA effects, HGCAMT (Heterosis Grouping by Combining Ability of Multiple Traits), and HSGCA (Heterotic Grouping based on Specific and General Combining Ability). The study identified HUZM-242 × CML-286 and HUZM-53 × CML-286 as crosses displaying higher grain yield compared to the check line DKC 7074 and exhibiting positive heterosis. The findings offer valuable guidance for maize breeding programmes by accurately identifying heterotic groups, enabling breeders to select inbred lines more likely to produce high-performing hybrids. This targeted selection reduces the number of necessary cross-breeding trials, saving time and resources. Additionally, hybrids derived from crosses between lines from different heterotic groups exhibit superior performance due to higher heterosis. These conclusions support advancements in maize breeding strategies, ultimately contributing to agricultural sustainability through increased productivity, resource efficiency, and economic benefits for farmers.

One of the most essential prerequisites in plant breeding is to have a maximum collection of germplasm materials with all sorts of variability. As a part of the programme under the All India Coordinated Research Projects on Spices, totally 196 germplasm accessions of small cardamom are being maintained as field gene bank repository at the Cardamom Research Station, Pampadumpara. Tropical evergreen forests of the Indian Western Ghats and Sri Lankan Central Highlands are recognized as the home of cardamom. The area and production of cardamom are maximum in Kerala followed by Karnataka and Tamil Nadu. Variations among the germplasm collections in morphological and biometrical characters as well as for yield have been studied and reported in this paper. Accessions with distinct morphological marker characters, such as compound panicle types, terminal panicle bearing, narrow leaf types, pink pseudostem types, dark green bold capsules with high-yield potential and biotic-stress tolerant types, are being evaluated and conserved in this repository. The assessment of genetic diversity is an essential prerequisite for undertaking crop breeding activities to evolve suitable area and region-specific variety. Sixty-seven cardamom accessions were studied for genetic diversity by evaluating 14 unique characters for 3 years (2016–2018). Almost all accessions have shown significant variability for most of the biometric and biotic stress characters. Results have indicated a greater magnitude of genetic diversity of small cardamom present among accessions representing whole evergreen tropical forest of the Western Ghats.

Taq polymerase system is one of the key success factors for genotyping by using semi-random marker types. Start codon targeted (SCoT) and sequence-related amplified polymorphism (SRAP) are semi-random markers that amplify more than one target at a time, like in multiplex PCR. Here, we compared the performance of five multiplex PCR kits (QIAGEN®, Thermo Scientific™, New England Biolabs, KAPA Biosystem and iNtRON Biotechnology) and Taq DNA polymerase from Vivantis as a representative common Taq polymerase. The PCR using three SCoT and three SRAP markers was performed in six plants, which were different in genome size, including three monocotyledons (rice, oil palm and onion) and three dicotyledons (holy basil, chilli pepper and eggplant). The overall results demonstrated consistent high performance of the Taq polymerase system with the multiplex PCR kit from KAPA Biosystem. Considered by plant, the multiplex PCR kit from KAPA Biosystem showed the best performance in holy basil, eggplant, oil palm and chilli pepper, whereas in rice, the Taq DNA polymerase from Vivantis generated better results than the KAPA Biosystem. In onion, multiplex PCR kit from Thermo Scientific™ showed the best performance among those tested, even if it did not perform well in the other plans. Different Taq polymerase systems might generate different band patterns, therefore using the same Taq polymerase system within one experimental dataset is recommended. The multiplex PCR kit from KAPA Biosystem is the best starting choice.

We successfully generated clear amplified fragment length polymorphism (AFLP) profiles of Anemone coronaria using only a single restriction enzyme (EcoR I). Four primer combinations generated 571 bands in 37 anemone accessions with an average 142.75 bands per primer combination. Polymorphism among the 37 samples was very high (98.15%). This high polymorphism showed that the one-enzyme AFLP method is effective for the assessment of genetic diversity as well as cultivar differentiation of anemone. We observed 26 bands which differentiated between fingerprints derived from leaf and corm DNA of eight plant individuals. However, the low percentage of such bands showed that anemone corms can also be used to evaluate anemone germplasm using AFLP markers.

The wild species of tomato Solanum pennellii (Lpa) is more tolerant to salt-induced oxidative stress than the cultivated species Solanum lycopersicum (Lem), due to the increase of several antioxidative metabolites and enzymes in this species under stress. The increase of reduced glutathione (GSH), one of these metabolites, in NaCl-treated Lpa, is due at least partly to the elevation of γ-glutamylcysteine synthetase (γ-ECS). Introgression line IL 8–3, which was found to include the Lpa orthologue of the γ-ECS gene (Lpa γ-ECS) in Lem's genetic background, was used to assign this gene to chromosome 8 and to assess its relative contribution to the effective antioxidative response of Lpa to stress. The growth of IL 8–3 and Lem plants responded similarly to NaCl and cadmium (Cd) stresses. In both genotypes, GSH and H2O2 levels responded also similarly to NaCl stress. NaCl and Cd stresses affected similarly the transcription of the γ-ECS gene in leaves of both IL 8–3 and Lpa plants. The effect of buthionine sulfoximine (BSO), a competitive inhibitor of the γ-ECS enzyme, on γ-ECS transcription was also similar in these two genotypes. Taken together, these results suggest that γ-ECS orthologues differ mainly in the regulation of their transcription and not at the post-transcriptional or translational levels. The mutation(s) led to these differences in the response of the two orthologues to the salinity and heavy metal stresses are expected to occur in a cis-regulatory element(s) located relatively close to γ-ECS.

The objective of this study was to investigate the effect of one cycle of seed regeneration on the conservation of genetic diversity in five Italian ryegrass landraces (Lolium multiflorum Lam.). Regeneration took place outdoors, in a sheltered site surrounded by tall Galician wheat, 20 m from the nearest source of alien pollen. A balanced mixture of seed (the same weight of seed per plant) was made from 90–100 plants harvested within each population. The conservation of allele frequencies was assessed by starch gel electrophoresis. Five enzyme systems from 78–153 plants per population were examined on slices of a single histidine–citrate starch gel. Each regenerated population differed from its original landrace in at least one of the five loci. The mean heterozygosity per locus was 0.45 for original and regenerated populations, and the mean number of alleles per locus was 3.7 and 3.6 for original and regenerated populations, respectively. There was no loss of common alleles (frequency >0.05) in the five regenerated populations compared with the original populations. Only three rare alleles (frequency < 0.05) were lost (e.g. alleles phosphoglucose isomerase (PGI)-2a, PGI-2c* and shikimate dehydrogenase (SDH)-1d in Padrón, Pravia and Luarca, respectively). No regeneration effect (P>0.05) was observed in the six agromorphological characters. However, a significant landrace effect was observed (P < 0.05) in the five agromorphological traits and the regenerated landraces deviated from the original landraces in 20% of direct comparisons. The results suggest that the method of regeneration used was not very suitable for maintaining the genetic integrity of the original landraces.

The allelic variations at glutenin loci could significantly affect the bread baking quality, and specific glutenin alleles might be closely associated with greater gluten strength, which, in turn, is related to superior bread baking quality. In this study, allelic variations at Glu-1, Glu-A3 and Glu-B3 loci were evaluated in 222 Korean wheat landraces using gene-specific polymerase chain reaction (PCR) markers. Ten alleles were identified at Glu-1 loci. Glu-A1c, Glu-B1b, and Glu-D1a or Glu-D1f alleles were predominantly found at the respective loci and their frequencies were 86.5, 87.8 and 96.9 %, respectively. Seven Korean wheat landraces carried the Glu-D1d allele, and only one Korean wheat landrace (IT173162) achieved 10 points for the Glu-1 score. Fifteen alleles were identified at Glu-A3 and Glu-B3 loci; Glu-A3c and Glu-B3d or Glu-B3i alleles were commonly found at the respective loci and their frequencies were 77.0, 33.3 and 37.8 %, respectively. Glu-B3 alleles exhibited the highest genetic diversity than other alleles, while Glu-B1 and Glu-A1 alleles exhibited the lowest genetic diversity than other alleles. Twenty Korean wheat landraces had the Glu-A3d and Glu-B3b, Glu-B3d, Glu-B3f, Glu-B3g or Glu-B3i alleles, which were correlated with superior bread baking quality. Among these wheat lines, two (IT59787 and IT236544) carried the Glu-D1d allele.

Nitrogen fertilizer and water are two major nutrients required for the optimal production of rice worldwide. The utilization of different irrigation techniques to save water and fertigation to maximize rice production has been the main focus. A field experiment was conducted to explore the responses of 16 rice varieties to different irrigation and nitrogen fertilizer regimes. Two nitrogen treatments, 270 kg ha−1 and 225 kg ha−1 (urea N ≥ 46.4%), and two irrigation regimes, 8.7 t ha−1 and 5.22 t ha−1, were applied three times. Plant height and the soil and plant analyser development (SPAD) values were measured throughout the growth period. The total yield and quality characteristics of the rice varieties were also determined. Based on the yield, the 16 rice varieties were divided into three groups: high yield (I), middle yield (II) and low yield (III) using cluster analysis. A positive correlation was found between the growth period and yield of these 16 rice varieties. In the water-deficient regime, the growth period of the 16 varieties was reduced by 1.68–2.93%. Furthermore, nitrogen- and water-deficient regimes had significant effects on the polishing rate, protein content and taste values of all varieties. At maturity stage under these regimes, plant height and chlorophyll SPAD values were decreased by 1.25–6.05% and 1.60–31.48%, respectively. Deficient nitrogen fertilization, along with appropriate irrigation, is an effective method for the efficient utilization of irrigation and fertilizer resources in rice-growing areas.

Sensitivity of alfalfa to acidity and aluminium (Al) toxicity in soil is the major limiting factor in broadening of its growing area. Due to lack of Al tolerance in primary alfalfa germplasm, there is a need for transfer of genes for Al tolerance from other Medicago germplasm. One of the identified sources of Al tolerance is M. sativa ssp. caerulea accession PI 464724, which was used as a female parent in our study. The objectives of this study were: (i) obtaining the tetraploid offspring from 2x–4x M. sativa ssp. caerulea – M. sativa ssp. sativa spontaneous crosses, and (ii) development of a breeding strategy for Al/acid tolerance in alfalfa, using M. sativa ssp. caerulea as a source of Al tolerance. Out of eleven fully developed plants, five were morphologically similar to M. sativa ssp. caerulae, while six plants were similar to M. sativa ssp. sativa. All tested plants were fertile, with the pollen viability ranging from 21.45 to 97.09% and the average number of ovules per plant from 8.80 to 12.29. Eleven SSR primer pairs confirmed the hybrid nature of M. sativa ssp. caerulae × M. sativa ssp. sativa offspring. Both the Cluster Analysis and the Principal Coordinates Analysis separated plants in the caerulae type from plants in the sativa type, with one exception. Strategies based on conventional and molecular marker breeding efforts could lead towards development of tolerant alfalfa cultivars and successful crop production on acidic, Al-contaminated soils.

Jujube is both consumed as a food source and medicinal plant in local markets. It is expected that different geographical populations of Ziziphus jujuba, differ in their genetic content as they grow in different ecological conditions. It is important to have detailed information on population genetic structure and the available genetic variability to make a proper germplasm collection of jujube. We have no data on jujube populations of Iran based on SCoT and REMAP molecular markers, and therefore we planned a population genetic study of these trees in 10 geographical areas. We used SCoT and REMAP molecular markers for our genetic investigation. We found the loci with a high value of Gst (1.00) in SCoT and REMAP markers that can be used in fingerprinting of jujube.

Gerbera is an important commercial flower crop in the world. Augmenting the genetic diversity is desirable for further improvement in Gerbera breeding programme. Thirty-seven (37) Gerbera accessions were evaluated and analysed for genetic variability, heritability, correlation and path coefficient analysis using yield and quality traits. Results showed that phenotypic coefficients were higher than genotypic coefficients of variation for all the characters. All the traits, except stalk and flower diameter, had high heritability (>60%) and genetic advance (>20%). Based on cluster analysis, the 37 accessions were grouped into seven clusters. Cluster I consists of the maximum number of genotypes (22), while clusters IV–VII are monogenotypic with unique traits. Cluster analysis (D2) showed wider genetic diversity within and between the clusters. The first four principal components (Eigenvalue >1) contributed 72.3% of the total variation. The number of leaves, number of flowers and flower stalk length contributed the most to genetic divergence. Flower yield showed a significant positive genotypic correlation with the number of leaves and suckers. The path analysis (genotypic) revealed that number of suckers, flower stalk diameter and flower stalk length contribute major positive direct effects on number of flowers. Therefore, the wide genetic variability existing in the germplasm may facilitate improvement in gerbera crops. Superior lines (RCGH-12, -22, -114, -117) with higher yield (>23 flowers/plant) and vase life (>5 days) could be promoted for commercial production under open field conditions. While RCGH 28 has a dwarf flower stalk that can be promoted for pots and decoration purposes.

The objectives of this study were to analyse the maize diversity in the southeast of Coahuila State in Mexico and to identify a representative subset that encompasses the majority of the diversity in the region of study. Seventy-seven native maize populations were first explored and given a race classification followed by a morphological description based on selected quantitative ear traits using 10 representative ears from the collected samples. The differences between maize populations from the adaptation area and the relationships between and within groups in the region of study indicate the usefulness of the ear traits to describe maize diversity. Two main groups were identified that summarized the maize diversity. The first group, the conical ear complex, includes populations adapted to highland altitudes (Conico Norteño Race). The second group, the cylindrical ear complex, represents populations adapted to lowland and intermediate altitudes (Raton and Tuxpeño Norteño). Using the phenogram, a subset of 18 out of the 77 maize populations (23.4%) was defined that accounts for the variation between and within the different race complexes. This subset also includes at least one representative population from each of the less represented types. The final subset, representing a sample of maize diversity, can be used to establish strategies for conservation and use, such as participatory conservation and management, or it can be used to develop breeding techniques for improving the land race populations within the region of study.

Buckwheat (Fagopyrum spp.) is an important crop in the high-altitude regions of the Northwest Indian Himalayas. The agro-climatic heterogeneity of this region offers a great deal of diversity in the agro-morphology of buckwheat species. In this study, a total of 61 accessions of Fagopyrum esculentum and Fagopyrum tataricum were characterized for 17 morphological (8 qualitative and 9 quantitative) traits. Significant differences (P < 0.0001) among all the traits were revealed by one-way analysis of variance. Further, significant phenotypic variability in both qualitative as well as quantitative traits was also observed. Both positive and negative correlations were observed between the traits of agronomic relevance. The principal component analysis (PCA) reveals about 69% variability among the first six components. The accessions were divided into two key clusters with numerous subclusters by considering the unweighted pair group method with arithmetic mean dendrogram. A cluster of 19 accessions was formed utilizing a PCA scatter plot indicating accessions with maximum values for important quality traits like plant height, leaf blade width, stem colour (red), primary branches, inflorescence length, flower colour (greenish-yellow), seed anthocyanin colour (green), seed shape (ovate) and seed weight. These accessions can be of vital significance for future buckwheat breeding programmes. The findings from the current study will form a favourable base for genetic resource management, improved cultivation and applications of buckwheat at the commercial level in the northwestern Himalayas of India.

Two aphid-transmitted RNA viruses, broad bean wilt virus 2 (BBWV2) and cucumber mosaic virus (CMV), are the most prevalent viruses in Korean pepper fields and cause chronic damage in pepper production. In this study, we employed a screening system for pathotype-specific resistance of pepper germplasm to BBWV2 and CMV by utilizing infectious cDNA clones of different pathotypes of the viruses (two BBWV2 strains and three CMV strains). We first examined pathogenic characteristics of the BBWV2 and CMV strains in various plant species and their phylogenetic positions in the virus population structures. We then screened 34 commercial pepper cultivars and seven accessions for resistance. While 21 pepper cultivars were resistant to CMV Fny strain, only two cultivars were resistant to CMV P1 strain. We also found only one cultivar partially resistant to BBWV2 RP1 strain. However, all tested commercial pepper cultivars were susceptible to the resistance-breaking CMV strain GTN (CMV-GTN) and BBWV2 severe strain PAP1 (BBWV2-PAP1), suggesting that breeding new cultivars resistant to these virus strains is necessary. Fortunately, we identified several pepper accessions that were resistant or partially resistant to CMV-GTN and one symptomless accession despite systemic infection with BBWV2-PAP1. These genetic resources will be useful in pepper breeding programs to deploy resistance to BBWV2 and CMV.

This study evaluated the morphological diversity of some Nigerian accessions of Bambara groundnut. Field experiments were conducted in Nigeria in two locations and the phenotypic variation of Bambara groundnut accessions evaluated in 3 years (2017–2020) using a randomized complete block design. Twenty-eight quantitative and 10 qualitative traits were observed. Twenty-three out of the 28 quantitative morphological traits showed significant differences. TVSu-589 (28.85) and TVSu-670 (28.57) had the highest plant height; TVSu-572 (121.52), TVSu-271 (113.10) and TVSu-336 (104.15) had the highest 100-seed weight. Genetic variations were also observed in seed colour, terminal leaflet shape, petiole colour and eye pattern. Principal component analysis showed PC1 constituting 23.36% and PC2 constituting 15.76% of the total variation, while the first eight principal components with eigenvalues ≥1 revealed 77.28% of the total variation. Cluster analysis grouped the accessions into four groups. Based on yield data in this study, accessions TVSu-594, TVSu-350, TVSu-336, TVSu-1242, TVSu-129, TVSu-14, TVSu-179, TVSu-2100, TVSu-261 and TVSu-589 were the best for yield and are recommended for further evaluation to improve yield. This study showed that a wide range of diversity exists in Bambara groundnut of Nigerian origin that could be useful for further utilization of genetic resources and improvement.

Cultivated sunflower (Helianthus annuus L.) pollen helps attract wild and managed bees needed to produce hybrid seed. Pollen quantity and grain size (≈quality) are affected by the environment, but are also heritable traits of interest for breeding. Florets from public inbred B-lines (maintainer) and R-lines (restorer) were used to evaluate pollen quantity and quality, test for trait correlations and determine if line development has changed pollen traits. Pollen quantity (≈25,000–67,000 grains per floret) and diameter (≈30–37 μm) were similar to previous reports and values of each parameter were correlated across years. Pollen quantity per floret was positively correlated with floret size (area; mm2) but floret sizes and pollen quantity were unrelated to pollen grain size. Groups of lines released relatively early (1968–1986) or late (1988–2006) did not differ in pollen quantity or size, and male (R-line) parents did not produce larger grains. The strong, positive correlation between floret size and pollen quantity reveals a possible trade-off because wild bees generally prefer sunflowers with shallower florets. The apparent lack of change in pollen quantity or pollen grain size over time (and lack of increased pollen size in R-lines relative to B-lines) suggests that the quantity and quality of pollen may not be limiting factors in the success of inbred lines or resulting hybrids. Though sunflower lines with larger florets contain more pollen, additional variation in pollen visible on sunflower heads may relate to the timing or completeness of pollen extrusion from anther tubes.

Mangrove fan palm is an endemic plant that grows well and has for a long period been related to traditional ceremonies in southern Thailand. It is an endangered plant with a slow growth and is difficult to propagate in mass production. Tissue culture technique can be used to produce a large number of plants within a short time and to preserve in vitro germplasm resulting in the plant not becoming extinct from natural habitats. Thus, the objectives of this research were to study effects of auxins and embryo preparation on somatic embryogenesis. The sterile immature zygotic embryo was cultured on MS medium with different types and concentrations of auxins. The results showed that 1 mg/l dicamba gave the best results in callus induction at 100% and callus diameter at 4.67 mm after 8 weeks of culture. For callus proliferation, callus chopped at 100 times and transferred to 0.1 mg/l dicamba containing oil palm culture medium gave the highest callus diameter at 10.33 mm after 4 weeks of culture and somatic embryos were also produced. Upon transferring somatic embryos to MS medium with 0.2 M sorbitol, a large number of various developmental stages of secondary somatic embryos were induced within 4 weeks. Therefore, the finding of this study could be highlighted that dicamba and chopping callus have an important role to induce callus and somatic embryo. This is the first report achieved on in vitro propagation of this plant and it will be beneficial for genetic conservation and biotechnological applications in the future.