Candidate Parents Research Articles

Parentage analysis of tea cultivars in Japan based on simple sequence repeat markers.

Tea cultivars have been bred by individual selection of landraces and by crossbreeding, but the validation of the parentage is limited. In this study, we performed parentage analysis of 79 tea cultivars in Japan based on SSR markers to confirm or identify the parent-offspring relationships among them. The effectiveness of nine SSR markers for parentage analysis was validated by comparing them to the existing cleaved amplified polymorphic sequence markers. The former markers were detectable more alleles than the latter. Simulation of parentage analysis of the tea cultivars predicted biparental origins for 12 cultivars (‘Houshun’, ‘Mie ryokuhou no. 1’, ‘Surugawase’, ‘Tenmyo’, ‘Yamanoibuki’, ‘Harumidori’, ‘Koushun’, ‘Minekaori’, ‘Okumusashi’, ‘Saemidori’, ‘Sofu’, and ‘Toyoka’), in the first five of which candidate parents of yet-to-be-defined pedigree were newly identified. Comparisons of a total of 41 SSR genotypes confirmed the newly-identified parentages of ‘Asahi’ for ‘Tenmyo’, ‘Rokurou’ for ‘Houshun’, ‘Surugawase’, and ‘Yamanoibuki’, and ‘Yamatomidori’ for ‘Mie ryokuhou no. 1’. The maternity of seven cultivars out of the 12 was also confirmed with chloroplast DNA sequences. Uniparental origins were confirmed for 25 cultivars. This parentage analysis has improved our knowledge of tea pedigrees and will aid in the development of new cultivars.

Identification of determinants of pollen donor fecundity using the hierarchical neighborhood model.

Individual differences in male reproductive success drive genetic drift and natural selection, altering genetic variation and phenotypic trait distributions in future generations. Therefore, identifying the determinants of reproductive success is important for understanding the ecology and evolution of plants. Here, based on the spatially explicit mating model (the neighborhood model), we develop a hierarchical probability model that links co-dominant genotypes of offspring and candidate parents with phenotypic determinants of male reproductive success. The model accounts for pollen dispersal, genotyping errors as well as individual variation in selfing, pollen immigration, and differentiation of immigrant pollen pools. Unlike the classic neighborhood model approach, our approach is specially designed to account for excessive variation (overdispersion) in male fecundity. We implemented a Bayesian estimation method (the Windows computer program available at: https://www.ukw.edu.pl/pracownicy/plik/igor_chybicki/1806/) that, among others, allows for selecting phenotypic variables important for male fecundity and assessing the fraction of variance in fecundity (R2 ) explained by selected variables. Simulations showed that our method outperforms both the classic neighborhood model and the two-step approach, where fecundities and the effects of phenotypic variables are estimated separately. The analysis of two data examples showed that in wind-pollinated trees, male fecundity depends on both the amount of produced pollen and the ability to pollen spread. However, despite that the tree size was positively correlated with male fecundity, it explained only a fraction of the total variance in fecundity, indicating the presence of additional factors. Finally, case studies highlighted the importance of accounting for pollen dispersal in the estimation of fecundity determinants.

Formulation of a decision support tool incorporating both genetic and non-genetic effects to rank young growing cattle on expected market value

While breeding indexes exist globally to identify candidate parents of the next generation, fewer tools exist that provide guidance on the expected monetary value of young animals. The objective of the present study was therefore to develop the framework for a cattle decision-support tool which incorporates both the genetic and non-genetic information of an animal and, in doing so, better predict the potential market value of an animal, whatever the age. Two novel monetary indexes were constructed and their predictive ability of carcass value was compared to that of the Irish national Terminal breeding index, typical of other terminal indexes used globally. A constructed Harvest index was composed of three carcass-related traits [i.e., 1) carcass weight, 2) carcass conformation and 3) carcass fat, each weighted by their respective economic value] and aimed at purchasers of animals close to harvest; the second index, termed the Calf index, also included docility and feed intake (weighted by their respective economic value), thus targeting purchasers of younger calves for growing (and eventually harvesting). Genetic and non-genetic fixed and random effect model solutions from the Irish national genetic evaluations underpinned all indexes. The two novel indexes were formulated using three alternative estimates of an animal's total merit for comparative purposes: 1) an index based solely on the animal's breed solutions, 2) an index which also included within-breed animal differences, and 3) an index which, as well as considering additive and non-additive genetic effects, also included non-genetic effects (referred to as production values [PVs]). As more information (i.e., within breed effects and subsequently non-genetic effects) was included in the total merit estimate, the correlations strengthened between the two proposed indexes and the animal's calculated carcass market value; the correlation coefficients almost doubled in strength when total merit was based on PV-based estimates as compared to the breed solutions alone. Including phenotypic live-weight data, collected during the animal's life, strengthened the predictive ability of the indexes further. Based on the results presented, the proposed indexes may fill the void in decision support when purchasing or selling cattle. In addition, given the dynamic nature of indexes, they have the potential to be updated in real-time as information becomes available.

SCREENING OF MAIZE (ZEA MAYS L.) INBRED LINES UNDER WATER DEFICIT CONDITIONS

Development of the selection criteria and selection of crop plant genotypes is a crucial and important task of plant breeders. The present study was designed to screen out the drought or water deficit tolerant maize genotypes. Fifty genotypes were taken from maize germplasm restored by the Department of Plant Breeding and Genetics University of Agriculture, Faisalabad, Pakistan. One set of genotypes were grown under 100% field capacity while other set at 50% field capacity in wire house conditions. The significant contrasts were observed in genotypes of various attributes under ordinary and stress timeframe. The traits root length and root shoot ratio by mass showed the high heritability and genetic advance and genotypic correlation with each other under water deficit condition provided the basis for the selection. The principle component analysis showed that the genotypes A545, AES204, WM13RA were chosen on the premise of better performance for most of the traits under study. These lines may be used in further breeding program as candidate parents for the development of drought tolerant hybrids.

DNA fingerprinting and genetic diversity analysis of world quinoa germplasm using iPBS-retrotransposon marker system

Quinoa is an important staple food crop for millions of impoverished rural inhabitants of the Andean region. Quinoa is considered a good source of protein,vitamins, minerals, and antioxidants. This study aimed to investigate the genetic diversity and population structure of world quinoa germplasm originating from 8 countries through the iPBS-retrotransposon marker system. Molecular characterization was performed using the 11 most polymorphic primers. A total of 235 bands were recorded, of which 66.8% were polymorphic. Mean polymorphism information content (PIC) was 0.410. Various diversity indices including mean effective number of alleles (1.269), mean Shannon's information index (0.160) and gene diversity (0.247) revealed the existence of sufficient amount of genetic diversity in studied germplasm. Bolivia-17 and Mexico-1 were found to be genetically distinct accessions and can be suggested as candidate parents for future breeding activities. Various diversity indices were also calculated among germplasm collection counries and the results clearly showed the existence of higher genetic diversity in Bolivian and Peruvian accessions. The model-based structure, neighbor-joining, and principal coordinate analysis (PCoA) grouped quinoa germplasm according to their collection country. Analysis of molecular variance (AMOVA) revealed that most of the variations (69%) in world quinoa germplasm are due to differences within populations. Findings of this study can be used for deeper understanding of the genetic relationship and in the determination of appropriate breeding and conservation strategies for quinoa.

Genotype by environment interaction for survival and harvest body weight between recirculating tank system and pond culture in Penaeus monodon

Genetic improvement of tiger prawn Penaeus monodon is challenging due to difficulties in breeding and rearing of this species in captive environments. To date, there have been very limited quantitative genetic studies in this species, especially genotype by environment (G × E) interaction between diverse farming systems (e.g., tank vs. pond). Therefore, the present study ran the long-term captive selection program for tiger prawn and obtained an in-depth pedigree of five generations (including base population and first generation) for genetic assessment of the environment impacts on two economically important traits in this species (i.e., survival and body weight at harvest). Originally, we evaluated the G × E interaction effect on survival and harvest weight between Biosecure Recirculating System (RAS) at the breeding nucleus and outdoor commercial ponds. Quantitative genetic analysis within mixed model methodology framework was carried out on 57,435 individual prawns (phenotype data from three latest generations, G2-G4) to examine possible effects of rearing environments on genetic parameters (heritability and correlations) for survival and body weight at harvest. The heritability (h2) for body weight was moderate (0.31–0.49) and differed slightly between the three testing environments. There were also significant heritable genetic variations of survival (h2 = 0.37–0.77) across the environments studied. The common full-sib effects accounted for 16 to 21% of total phenotypic variation for body weight and 11 to 18% for survival. Genetic correlations between body weight and survival were positive (0.23–0.46) in this population of tiger prawn. To examine the G × E interaction effect on survival and harvest body weight, the trait expressions in each environment were treated as separate traits and bi-variate models were used to estimate genetic correlations between homologous characters. An important finding of this study was that the between-environment genetic correlations for both body weight and survival were medium to high (0.56–0.70) between outdoor ponds; however, the estimates were low to moderate (0.17–0.31) between indoor RAS in the nucleus and outdoor ponds under field conditions. In summary, the moderate heritability for body weight and survival suggest that long-term response to selection can be achieved in this population of tiger prawn, and that the effects of rearing environments should be taken into consideration when conducting genetic improvement programs for this species, specifically the management of candidate parents to produce the next generation for selection.

Parentage and relatedness reconstruction in Pinus sylvestris using genotyping-by-sequencing

Estimating kinship is fundamental for studies of evolution, conservation, and breeding. Genotyping-by-sequencing (GBS) and other restriction based genotyping methods have become widely applied in these applications in non-model organisms. However, sequencing errors, depth, and reproducibility between library preps could potentially hinder accurate genetic inferences. In this study, we tested different sets of parameters in data filtering, different reference populations and eight estimation methods to obtain a robust procedure for relatedness estimation in Scots pine (Pinus sylvestris L.). We used a seed orchard as our study system, where candidate parents are known and pedigree reconstruction can be compared with theoretical expectations. We found that relatedness estimates were lower than expected for all categories of kinship estimated if the proportion of shared SNPs was low. However, estimates reached expected values if loci showing an excess of heterozygotes were removed and genotyping error rates were considered. The genetic variance-covariance matrix (G-matrix) estimation, however, performed poorly in kinship estimation. The reduced relatedness estimates are likely due to false heterozygosity calls. We analyzed the mating structure in the seed orchard and identified a selfing rate of 3% (including crosses between clone mates) and external pollen contamination of 33.6%. Little genetic structure was observed in the sampled Scots pine natural populations, and the degree of inbreeding in the orchard seed crop is comparable to natural stands. We illustrate that under our optimized data processing procedure, relatedness, and genetic composition, including level of pollen contamination within a seed orchard crop, can be established consistently by different estimators.

Pipette and paper: Combining molecular and genealogical methods to assess a Nile tilapia (Oreochromis niloticus) breeding program

[Extract] Aquaculture selective breeding programs employ a closed nucleus mating strategy whereby animals displaying sought-after characteristics are mated to produce next generation offspring with increased pre-valence of desirable phenotypes. Offspring exhibiting high genetic merit for favorable traits are then usually chosen as candidate parents for the subsequent breeding cycle. The selective breeding process is replicated each succeeding generation in order to accumulate genetic gain within the breeding population. The long term success of these closed breeding systems is dependent on a number of factors: including, the heritability of a trait, the intensity of selection, the additive genetic variance observed in the founding population, and the amount of additive genetic variance maintained over subsequent generations (Falconer et al., 1996; Loughnan et al., 2016). If breeding practices are not properly managed, the number of animals with high relatedness will increase (Gjedrem and Baranski, 2009b), leading to a substantial loss of genetic diversity over subsequent generations (Pante et al.,2001). The maintenance of genetic diversity is critical to accommodate current and future changes in production environments, and if left unchecked, it can lead to inbreeding through increased homozygosity and deleterious fitness consequences associated with inbreeding depression (Pante et al., 2001). This loss of genetic diversity can also hamper progress within the selective breeding program as it limits the amount of genetic variance available for selection (Falconer, 1960).

CORRELATION COEFFICIENTS BETWEEN PHYSIOLOGY, BIOCHEMISTRY, COMMON ECONOMIC TRAITS AND YIELD OF COTTON CULTIVARS UNDER FULL AND DEFICIT IRRIGATED CONDITIONS.

Drought is a common abiotic stress that considerably limits crop production. The objective of this study is to explore the influence of water deficiency on the yield and physiologic-biochemical in upland cotton cultivars (Gossypium hirsutum L). Cotton cultivars, 'Ishonch', 'Navbakhor-2','C-6524' and 'Tashkent-6' were selected to study the relationships among their physiologic, biochemical and yield attributes during water deficiency. Deficit irrigation was designed by modifying the traditional watering protocol to reduce water use. Results indicate that cotton cultivars respond differently to water deficit stress. Water deficit significantly influenced plant valuable economic traits and yield in four cultivars. However, yield components such as the number of bolls per plant, seed number per boll, mass of boll per plant and productivity plant yield were significantly reduced only in and C-6524 and Tashkent-6. The malondialdehyde decreased and total chlorophyll, chlorophyll “a” increased in 'Ishonch' and Navbakhar-2 under deficit irrigation conditions. The direct relationship between physiology, biochemistry, valuable economic traits, and yield may be a useful selection criterion for determining candidate parents for cotton drought tolerance breeding.

Multiplex PCR Sets of Novel Microsatellite Loci for Iwagaki Oyster Crassostrea nippona and Their Application in Parentage Assignment

Iwagaki oyster, Crassostrea nippona, widely distributes along the seashore of Eastern Asia, and has been considered to be a potential breeding species due to its delicious taste and high commercial value. In order to study its genetic background and population structure, we developed 46 novel polymorphic microsatellite markers using next-generation sequencing technique and characterized them in 30 individuals. The number of alleles ranged from 3 to 22, while the observed and expected heterozygosities varied from 0.133 to 1.000 and 0.455 to 0.949, respectively. Fifteen microsatellite markers were selected and grouped into five highly informative multiplex PCRs for C. nippona. We evaluated and validated these multiplex PCRs in a cultured population including 173 candidate parents and 486 offspring. In actual parentage analysis, 80% of the offspring were correctly assigned to their parental pairs using three multiplex PCRs. Furthermore, the success rate of parentage assignment reached 96% when the other two multiplex PCRs were added. These 46 microsatellite loci with high variability and the five multiplex PCRs described here provide a powerful tool for pedigree reconstruction, resource conservation and selective breeding program of C. nippona.

Small Neotropical primates promote the natural regeneration of anthropogenically disturbed areas

Increasingly large proportions of tropical forests are anthropogenically disturbed. Where natural regeneration is possible at all, it requires the input of plant seeds through seed dispersal from the forest matrix. Zoochorous seed dispersal – the major seed dispersal mode for woody plants in tropical forests – is particularly important for natural regeneration. In this study, covering a period of more than 20 years, we show that small New World primates, the tamarins Saguinus mystax and Leontocebus nigrifrons, increase their use of an anthropogenically disturbed area over time and disperse seeds from primary forest tree species into this area. Through monitoring the fate of seeds and through parentage analyses of seedlings of the legume Parkia panurensis from the disturbed area and candidate parents from the primary forest matrix, we show that tamarin seed dispersal is effective and contributes to the natural regeneration of the disturbed area.

A mating advice system in dairy cattle incorporating genomic information

This study investigated the effects of alternative mating programs that incorporate genomic information on expected progeny herd performance and inbreeding, as well as methods to include un-genotyped animals in such mating programs. A total of 54,535 Holstein-Friesian cattle with imputed high-density genotypes (547,650 SNP after edits) were available. First, to quantify the accuracy of imputing un-genotyped animals (often an issue in populations), a sub-population of 729 genotyped animals had their genotypes masked, and their allele dosages were imputed, using linear regression exploiting information on genotyped relatives. The reference population for imputation included all genotyped animals, excluding the 729 selected animals and their sires, dams, and grandsires, and had either (1) their sires' genotypes, (2) their dams' genotypes (3) both their sires' and their dams' genotypes, or (4) both their sires' and maternal grandsires' genotypes introduced into the reference population. The correlations between true genotypes and the imputed allele dosages ranged from 0.58 (sire only) to 0.68 (both sire and dam). A herd of 100 cows was then simulated (1,000 replicates) from the sub-population of 729 imputed animals. The top 10 bulls from the genotyped population, based on their total genetic merit index (TMI) were selected to be used as sires. Three mating allotment methods were investigated: (1) random mating, (2) sequential mating based on maximizing only the expected TMI of the progeny, and (3) linear programming to maximize a generated index constructed to maximize genetic merit and minimize expected progeny inbreeding as well as intra- and inter-progeny variability in genetic merit. Relationships among candidate parents were calculated using either the pedigree relationship matrix or the genomic relationship matrix; the latter was constructed using either the true genotypes of both parents or the true genotypes of the sire plus the imputed allele dosages of the dam. Using the genomic co-ancestry estimates resulted in lower average herd expected genomic inbreeding levels compared with using the pedigree-based co-ancestry estimates. Additionally, if the dams were not genotyped, using their imputed allele dosages also resulted in lower average herd expected inbreeding levels compared with using the pedigree co-ancestry estimates. The inter-progeny coefficient of variation for selected traits, milk and fertility, estimated breeding values were reduced by 12 to 65% using the linear programing method compared with sequential mating.

Mobile genomic element diversity in world collection of safflower (Carthamus tinctorius L.) panel using iPBS-retrotransposon markers.

Safflower (Carthamus tinctorius L.) is a multipurpose crop of dry land yielding very high quality of edible oil. Present study was aimed to investigate the genetic diversity and population structure of 131 safflower accessions originating from 28 different countries using 13 iPBS-retrotransposon markers. A total of 295 iPBS bands were observed among which 275 (93.22%) were found polymorphic. Mean Polymorphism information content (0.48) and diversity parameters including mean effective number of alleles (1.33), mean Shannon’s information index (0.33), overall gene diversity (0.19), Fstatistic (0.21), and inbreeding coefficient (1.00) reflected the presence of sufficient amount of genetic diversity in the studied plant materials. Analysis of molecular variance (AMOVA) showed that more than 40% of genetic variation was derived from populations. Model-based structure, principal coordinate analysis (PCoA) and unweighted pair-group method with arithmetic means (UPGMA) algorithms clustered the 131 safflower accessions into four main populations A, B, C, D and an unclassified population, with no meaningful geographical origin. Most diverse accessions originated from Asian countries including Afghanistan, Pakistan, China, Turkey, and India. Four accessions, Turkey3, Afghanistan4, Afghanistan2, and Pakistan24 were found most genetically distant and might be recommended as a candidate parents for breeding purposes. The findings of this study are most probably supported by the seven similarity centers hypothesis of safflower. This is a first study to explore the genetic diversity and population structure in safflower accessions using the iPBS-retrotransposon markers. The information provided in this work will therefore be helpful for scientists interested in safflower breeding.

Genome Sequencing of Blacklip and Greenlip Abalone for Development and Validation of a SNP Based Genotyping Tool.

Abalone breeding in southern Australia often involves the production of interspecies hybrids through crossing blacklip (Haliotos rubra) and greenlip (H. laevigata) parental populations. To assist applied breeding and investigate genetic divergence, this study applied genome sequencing and variant detection to develop and validate a SNP genotyping tool. Skim short read Illumina sequencing was performed using 24 individuals from each of the two parental species and a hybrid population. Raw reads were assembled into three population specific pools (each 12–15 fold coverage), before mapping was performed against a draft greenlip abalone reference genome. Variant detection identified 22.4 M raw variants across the three populations (SNP and indels), suggesting they are highly heterozygous. First stage filtering defined a high quality SNP collection of 2.2 M variants independently called in each of the three populations. Second stage filtering identified a much smaller set of variants for assay design and genotyping using a validation set of 191 abalone of known population and pedigree. Comparison of allele frequency data revealed a high proportion of SNP (43%) had divergent allele frequency (< 0.2) between the two parental populations, suggesting they should have utility for parentage assignment. A maximum likelihood approach was used to successfully assign 105 of 105 progeny to their known true parent amongst a set of 86 candidate parents, confirming the genotyping tool has utility for applied breeding. Analysis of pairwise allele sharing successfully discriminated animals into populations, and PCA of genetic distance grouped the hybrid animals with intermediate values between the two parental populations. The findings present a library of DNA polymorphism of utility to breeding and ecological application, and begins to characterize the divergence separating two economically important aquaculture species.

Corrigendum to: Wild seedlings of a tree endemic on granite outcrops show no evidence of inbreeding depression

Plant communities on granite outcrops are characterised by high biodiversity and endemism, and strong population genetic structuring. The floristic diversity and structure of inselberg flora receives much attention in international conservation research, yet our understanding of how recruitment influences population genetic structure of plants endemic to granite outcrops is limited. To determine the immediate genetic consequences of recruitment and to quantify mating and dispersal patterns by parentage analysis, I conducted an opportunistic study following a wildfire in a stand of the lignotuberous tree Eucalyptus caesia Benth. (Myrtaceae) at Boyagin Nature Reserve. The entire adult stand (n=180) plus seedlings (n=115) were genotyped with 14 microsatellite loci. Compared with adults, seedlings had low heterozygosity and a high inbreeding co-efficient, but similar levels of allelic diversity. There was no evidence of post-germination selection against homozygous seedlings over the 20 month survey period. Seedlings that resulted from cross-pollination were more heterozygous than seedlings resulting from selfing, but could not be distinguished based on height measurements or survivorship. Parentage analysis in CERVUS revealed mostly limited seed dispersal, assuming that candidate parents closest to seedlings were the maternal parent. By comparison, pollen movement was more extensive, yet still restricted to plants within the stand. Recruitment has increased the population size, but appears insufficient to enhance genetic diversity in the Boyagin stand of E. caesia. Nonetheless, E. caesia appears adept at persisting as extremely small populations.

Parentage assignment with genotyping-by-sequencing data.

In this paper, we evaluate using genotype‐by‐sequencing (GBS) data to perform parentage assignment in lieu of traditional array data. The use of GBS data raises two issues: First, for low‐coverage (e.g., <2×) GBS data, it may not be possible to call the genotype at many loci, a critical first step for detecting opposing homozygous markers. Second, the amount of sequencing coverage may vary across individuals, making it challenging to directly compare the likelihood scores between putative parents. To address these issues, we extend the probabilistic framework of Huisman (Molecular Ecology Resources, 2017, 17, 1009) and evaluate putative parents by comparing their (potentially noisy) genotypes to a series of proposal distributions. These distributions describe the expected genotype probabilities for the relatives of an individual. We assign putative parents as a parent if they are classified as a parent (as opposed to e.g., an unrelated individual), and if the assignment score passes a threshold. We evaluated this method on simulated data and found that (a) high‐coverage (>2×) GBS data performs similarly to array data and requires only a small number of markers to correctly assign parents and (b) low‐coverage GBS data (as low as 0.1×) can also be used, provided that it is obtained across a large number of markers. When analysing the low‐coverage GBS data, we also found a high number of false positives if the true parent is not contained within the list of candidate parents, but that this false positive rate can be greatly reduced by hand tuning the assignment threshold. We provide this parentage assignment method as a standalone program called AlphaAssign.

A Novel RPL Algorithm Based on Chaotic Genetic Algorithm.

RPL (routing protocol for low-power and lossy networks) is an important candidate routing algorithm for low-power and lossy network (LLN) scenarios. To solve the problems of using a single routing metric or no clearly weighting distribution theory of additive composition routing metric in existing RPL algorithms, this paper creates a novel RPL algorithm according to a chaotic genetic algorithm (RPL-CGA). First of all, we propose a composition metric which simultaneously evaluates packet queue length in a buffer, end-to-end delay, residual energy ratio of node, number of hops, and expected transmission count (ETX). Meanwhile, we propose using a chaotic genetic algorithm to determine the weighting distribution of every routing metric in the composition metric to fully evaluate candidate parents (neighbors). Then, according to the evaluation results of candidate parents, we put forward a new holistic objective function and a new method for calculating the rank values of nodes which are used to select the optimized node as the preferred parent (the next hop). Finally, theoretical analysis and a series of experimental consequences indicate that RPL-CGA is significantly superior to the typical existing relevant routing algorithms in the aspect of average end-to-end delay, average success rate, etc.

Paternity analysis using SSR markers reveals that the anthocyanin-rich tea cultivar ‘Ziyan’ is self-compatible

Most tea plants (Camellia sinensis) are self-incompatible. Self-incompatibility is critical for preventing inbreeding depression and maintaining genetic diversity, but it can hinder breeding and genetic studies. Originally, the propose of this study was to identify fathers of 16 elite F1 individuals derived from open-pollinated seeds of an anthocyanin-rich tea cultivar ‘Ziyan’. In order to achieve this, 41 candidate parents and 16 F1 individuals were genotyped with 15 polymorphic SSR markers. Using exclusion and likelihood methods, fathers of 12 individuals were identified at 95% level of confidence. Surprisingly, the results showed that eight individuals were from self-crossing of ‘Ziyan’. Additional 36 SSR markers were used to further confirm selfing and the results were consistent, demonstrating that ‘Ziyan’ is self-compatible. As expected, the degrees of heterozygosity of the eight selfing individuals were significantly lower than ‘Ziyan’ and other tea accessions. This is the first report of a clonal cultivar of C. sinensis being self-compatible under open-pollination conditions and verified using DNA-based markers. Therefore, ‘Ziyan’ and its selfing offspring will be valuable materials for both genetic studies and breeding in C. sinensis.

Exploring the genetic diversity and population structure of Turkish common bean germplasm by the iPBS-retrotransposons markers

Present study was aimed to investigate the genetic diversity and population structure of Turkish common bean germplasm. A total of 96 bean genotypes were characterized with iPBS-retrotansposons that yielded a mean polymorphism information contents of 0.8. Mean gene diversity and Shannon information index were 0.14 and 0.25, respectively. Neighbor joining analysis divided the bean genotypes into two main group (A and B) according to their geographical regions, growth habits and seed size. Bingol-l7, Sivas-14 and Hakkari-11 genotypes were found very distinct and can be used as candidate parents for the bean breeding. The higher efficiency and reproducibility of iPBS-retrotransposons was witnessed in common bean as compared to earlier studies using the same marker system. Results of this study will boost up the investigators for genotyping the larger germplasm of common bean with minimum laboratory infrastructure in developing and least developed countries.

Reproductive phenology of tea (&lt;i&gt;Camellia sinensis&lt;/i&gt; (L.) O. Kuntze) cultivars in Sri Lanka

Reproductive phenological attributes of the tea (Camellia sinensis (L.) O. Kuntze) plant have not been paid adequate attention until recently as the plant is being maintained continuously in the vegetative phase for commercial harvesting. However, with the introduction of improved seeds as an alternative planting material to adapt climate change scenarios and with recent advances of controlled hybridization, extensive studies on those aspects become a necessity. Therefore, the present study was conducted to assess the reproductive phenology of ten selected parental cultivars from a representative sample of three tea seed gardens; Salawa, Rembukkanda and Reucastle. Reproductive phenophases were visually rated on a non- parametric scale (0-5) monthly, for a period of 3 consecutive years. Ratings were subsequently converted into an index which represented both synchrony and intensity of phenophases. Study identified the periodicity, synchrony and intensity of reproductive phenophases in relation to the rainfall pattern of the area. Major flowering period was from September to December and major fruiting period was from April to August. The values of indices reflected significant variations of the phenological behavior among the different parental cultivars. The profuse fruit setters and profuse flower setters among the parental cultivars have been identified through the study. The information would be utilized as a base material in selecting suitable parental combinations for future gardens to ensure optimum productivity. Based on the overall results, phenological calendar and phenograms were constructed to facilitate the garden management and seed collection. The information generated could be utilized in controlled hybridization programmes to select candidate parents and to decide the timelines.