Citrus aurantium also known as sour orange or bitter orange is among important Citrus species of the angiosperm subfamily Aurantioideae of the Rutaceae family. Due to importance of Citrus species as the source of food and medicine, they have been subject of been extensive genetic studies throughout the world. Sour orange plants are cultivated in the north and south parts of Iran but we have very limited genetic data on them. Therefore, the present study was conducted with the aim to study the population genetics of these important fruit plants in the country and provide information on their genetic structure and diversity. We used SCoT molecular markers in 61 plants of 12 sour orange populations. We obtained 33 SCoT bands of which one to two private bands were observed in populations 1 and 5. Genetic diversity parameters determine in the studied populations revealed a low to moderate genetic diversity. Genetic grouping of the populations by UPGMA dendrogram and multidimensional scaling identified two major genetic groups. The studied populations differed significantly in their genetic content as revealed by AMOVA. Distinguishing SCoT loci are identified by Neis'and Gst as well as DAPC analysis. Some of the SCoT loci were significantly associated with geographical variables as revealed by RDA and LFMM analyses.

Panax L., renowned as ginseng genus, is a famous medicinal group of family Araliaceae. Within this genus, the taxa of Panax bipinnatifidus complex are mainly distributed in Himalayas and Hengduan Mountain areas. Due to the complex evolutionary history and short-term rapid radiation, the relationships among species within the complex have not been clearly resolved, and the taxa identification is difficult due to the intermediate morphological traits. This study aimed to use the available restriction-site associated DNA sequence data from 29 individuals of P. bipinnatifidus complex to mine high-polymorphic simple sequence repeat (SSR) markers, with the goal of evaluating their utility in taxa identification. Eleven polymorphic SSR loci were ultimately selected and validated through polymerase chain reactions amplifying across 63 individuals of P. bipinnatifidus complex and 13 individuals of three outgroup species. The subsequent genetic diversity analysis uncovered 76 alleles in total, ranging from 5 to 15 per locus. Observed heterozygosity spanned 0.241–0.512, while expected heterozygosity ranged between 0.345 and 0.644. The genetic kinship analysis revealed a sister relationship between Panax zingiberensis and Panax vietnamensis. The analysis result also supported the classification of samples from Hunan and Hubei provinces into a single genetic unit within the P. bipinnatifidus complex. These newly developed SSR markers will facilitate the identification of wild ginseng plants.

This study investigates the impact of environmental factors and genotype-by-environment interactions (GEI) on the expression of maydis leaf blight (MLB) resistance in a diverse maize germplasm comprising 359 genotypes. Extensive field trials were conducted, involving artificial inoculations and disease scoring across two locations over two years. Using genotype and genotype–environment (GGE) biplot analysis based on the site regression model (SREG), we identified stable MLB-resistant 10 donors with consistent genotypic responses. These inbred lines, which consistently exhibited disease scores of ⩽3 across locations, are recommended as potential parents for breeding MLB-resistant varieties. Furthermore, the identification of a non-crossover interaction and high correlations among testing locations allowed us to define a single mega-environment for the initial screening of MLB resistance in a large set of maize germplasm. This study suggests that initial screenings can be efficiently conducted in one representative location, with validation of resistant lines at multiple sites during advanced breeding stages. This approach optimizes the use of land, labour and resources in MLB resistance testing.

Kokum [Garcinia indica (Thouars) Choisy] is a multi-purpose tree with culinary, cosmetics and pharmaceutical uses found popular in Konkan region of India. ICAR-NBPGR Regional Station, Thrissur made a systematic exploration and collection missions on kokum over a period from 1987–2004 and collected 31 accessions from various parts of Konkan region to characterize them using morphological characters and also to investigate their flowering and fruiting behaviour. Totally, 85 trees planted in Field Gene Bank in which only 67 trees (23 accessions) survived during field establishment. Among them, 32 (47.8%) were male and remaining 25 identified as female (37.3%) and 10 as co-sexual (14.9%). Fruit bearing ability noticed only in both female and co-sexual trees with huge variation in fruits. Morphological characterization of 33 trees with fruiting (23 accessions) for 35 morphological traits revealed presence of considerable amount of variation among them on basis of CV%. Highest positive correlation observed between fresh seed weight and fresh kernel weight (0.92). Cluster analysis formed four major clusters with Cluster I and II comprising male/bisexual genotypes and Cluster III and IV with female genotypes and it clearly distinguished male/bisexual genotypes from female ones. PCA analysis accounted 65.6% of genetic variation present among accessions by first three most informative PCs. Superior accessions identified for important traits will be more useful in industrial aspects of preparing kokum butter and juice. Further, seasonal difference identified in fruiting and maturity of fruits well-before onset of monsoon may be exploited by kokum industries for drying and processing of fruits.

Nutmeg (Myristica fragrans Houtt; family: Myristicaceae) is an important tree spice of great export value due to the presence of secondary metabolites with scope in health, wellness and cosmetic industries. Its dioecious in nature due to which it is propagated by budding and grafting which requires specialised skill and as a result authentic planting material production is very expensive. Based on the constant demand from farmers and stakeholders for a suitable, fast and easy technique for determining the authenticity of nutmeg varieties, an attempt was made to develop morphological and molecular markers for the identification of three commercial varieties that are in high demand in India; viz. IISR Vishwashree, IISR Keralashree, Sindhushree and a monoecious nutmeg (MN) accession, along with their biochemical profiles. Among the various morphological characters as per distinctiveness, uniformity and stability guidelines, the varieties showed distinctness mainly in leaf shape, shape of female flowers, fruit shape and seed shape. Out of 35 ISSR primers screened, six primers viz., IS 02, ISSR 12, ISSR 05, ISSR 14, ISSR 01 and UBC 834 generated clear, unique reproducible polymorphic bands capable of distinguishing the varieties. Among the varieties analysed, MN was found to be superior in terms of seed butter and essential oil in nut, mace and leaves. IISR Vishwashree was on par with MN in nut essential oil content. IISR Keralashree was superior in terms of oleoresin in nuts and mace. The morphological and molecular markers identified may be used for effective checking of authenticity of planting materials of commercially grown nutmeg varieties.

Uncaria rhynchophylla (Rubiaceae), a woody liana with significant medicinal value, has been used as a traditional Japanese and Chinese medicine. While effective seed production is required for breeding and efficient seedling production, the physiology of sexual reproduction remains largely unknown in this species. Therefore, we first observed the flowering behaviour, and next attempted artificial pollination using flowering individuals in a greenhouse. In this study it became clear that this species sets seeds by allogamy, but not by autogamy. The obtained seeds showed about a 90% germination rate. We also examined seed desiccation tolerance and storage conditions which are important to preserve the genetic resources. Seeds of this species were found to have a characteristic of the orthodox type, having high desiccation tolerance. Seeds after 6 months of storage at + 22, −20 and −160°C showed comparable germination rates to the seeds before storage.

Walnut (Juglans regia L.) is one of the oldest and most economically important edible nut species due to its high nutritional value. Iran is known as one of the most important centres of the origin and diversity of walnuts worldwide. This research was carried out to determine the genetic relationships of some old walnut genotypes in Iran in order to select superior genotypes and better conserve them. The results of morphological evaluation of the fruits showed that the highest coefficients of variation were related to nut weight, kernel weight, percentage kernel, thickness and weight of the shell, and thickness and weight of the packing tissue in both years. The average morphological traits among the studied genotypes were different, such that the highest nut weights in the first and second years were 15.59 and 14.79 g and the corresponding lowest values were 7.37 and 7.79 g, respectively. The highest and lowest kernel weights were observed in the first years to be 8.09 and 3.80 g and in the second years were 6.94 and 2.65 g, respectively. The highest kernel percentages in the first and second years were 64.97 and 59.79% and the lowest percentages were 39.52 and 27.80% in the first and second years, respectively. Molecular evaluation results showed that the 16 start codon of target (SCoT) primers amplified a total of 166 bands with an average of 10.44 bands per primer. The number of polymorphic bands was changed from 2 to 19 in primers SCoT-19 and SCoT-15. The average polymorphism information content value was 0.30 and the highest amount of this index (0.36) was observed in SCoT-14 and SCoT-19 primers. The results of principal component analysis and analysis of molecular variance indicated the presence of relatively high diversity within the investigated genotypes. The amount of genetic diversity within the investigated regions was 84% and that between areas was 16%. Based on the obtained results, it was concluded that SCoT markers could provide helpful information on the genetic relationships among walnut genotypes, which can be used in future walnut breeding and conservation programmes.

Discriminatory morpho-metric features are obvious on legume seeds. This study utilized seven quantitative and 11 qualitative seed traits to characterize 139 African yam bean (AYB) breeding lines which were developed through single seed descent procedure. The seven quantitative data were subjected to analysis of variance, their means were combined with qualitative scores for genetic distance, principal component (PC) and clustering analyses. Significant (P ≤ 0.001) variation existed among the breeding lines for the seven traits. Mean ranges of seed length (SL), width (SW), thickness (ST) and a single seed weight (SSW) among the 139 breeding lines were respectively: 6.77–10.22 mm, 5.70–7.86 mm, 4.96–7.45 mm and 0.15–0.42 g. Positive and significant (P ≤ 0.05) genotypic correlation existed among SSW, SL, SW and ST. Seed colours, pattern, shapes, sizes, surface texture, brilliance varied among the breeding lines. Ranges of phenotypic and genotypic coefficient of variation and broadsense heritability were: 5.49–23.84%, 2.95–19.88% and 28.91–69.54% respectively. Fourteen (quantitative and qualitative) traits contributed higher (≥ 0.30) eigenvector loadings to the first three PC axes which explained 57.9% of the total variation among the breeding lines. Similarity among the lines was 0.75. Four clusters ensued in the dendrograph and each group had genetic similarities of: 0.85 (I), 0.82 (II), 0.78 (III) and 0.80 (IV). This research unveiled significant variation among AYB breeding lines with promising reliability for breeding opportunities of the qualitative and quantitative seed traits, which could contribute to higher grain yield and acceptability.

Wild species of rice possess tremendous genetic variations and harbour resistance genes for biotic stresses. Bacterial blight (BB), caused by Xanthomonas oryzae pv. oryzae (Xoo), is a major disease affecting rice production globally. The current study characterized 116 accessions from 17 species of Oryza for BB disease during three seasons viz., kharif 2020, rabi 2020–21, kharif 2021 using an isolate of Xanthomonas oryzae pv. oryzae (Xoo) strain IX-020. A total of 40 accessions including Oryza rufipogon, O. nivara, O. officinalis and O. australiensis showed consistence resistance to the bacterial blight disease across the seasons. These accessions were further subjected to molecular characterization using 11 Xa genes viz., Xa4, xa5, xa13, Xa21, Xa23, Xa27(t), Xa32(t), Xa33, Xa35(t), Xa38 and xa41 with gene-specific markers to ascertain the novelty. Some key resistance genes such as Xa4, Xa23, Xa27(t), Xa32(t), Xa33, Xa35(t) and xa41 were detected in multiple accessions, with O. rufipogon and O. eichingeri harbouring particularly complex combinations of these genes. Notably, several accessions viz., IC521672 (O. nivara), EC861665 (O. officinalis), EC861677 (O. latifolia), EC861711 (O. punctata) and EC861738 (O. eichingeri) did not show the presence of any known genes indicating the possibility of novel genetic loci conferring BB resistance in these wild species. These promising accessions identified in the study are potential novel sources for bacterial leaf blight resistance in rice and will be useful for the development of durable bacterial blight resistance rice cultivars.