Paternal Parent Research Articles

Inheritance of evolved clethodim resistance in Lolium rigidum populations from Australia.

In Australia, the extensive use of clethodim for the control of Lolium rigidum has resulted in the evolution of many clethodim-resistant L. rigidum populations. Five clethodim-resistant populations of L. rigidum were analysed for the inheritance of clethodim resistance. Reciprocal crosses were made between resistant (R) and susceptible (S) populations. Within crosses, dose-responses of reciprocal F1 families of all populations except A61 were similar to each other, indicating that clethodim resistance in these populations is encoded on the nuclear genome. The level of dominance observed in the dose-response experiments ranged from partial to complete within the herbicide rate used. In the A61 population, within each cross, the response of F1 from the maternal and paternal parent was different, indicating that resistance is inherited through the female parent. All backcross populations segregated in a different manner. Only one population, FP, fitted a single-gene model (1:1). Two populations fitted two-gene models: a 3:1 inheritance model for F4 and a 1:3 inheritance model for A91. For population E2, no clear pattern of inheritance was determined, suggesting more complex inheritance. The results of this study indicate that different patterns of clethodim resistance in L. rigidum exist. © 2016 Society of Chemical Industry.

Transcriptome analyses of seed development in grape hybrids reveals a possible mechanism influencing seed size.

BackgroundSeedlessness in grape (Vitis vinifera) is of considerable commercial importance for both the table grape and processing industries. Studies to date of grape seed development have been made certain progress, but many key genes have yet to be identified and characterized.ResultsIn this study we analyzed the seed transcriptomes of progeny derived from the V. vinifera seeded maternal parent ‘Red Globe’ and the seedless paternal parent ‘Centennial seedless’ to identify genes associated with seedlessness. A total of 6,607 differentially expressed genes (DEGs) were identified and examined from multiple perspectives, including expression patterns, Gene Ontology (GO) annotations, pathway enrichment, inferred hormone influence and epigenetic regulation. The expression data of hormone-related genes and hormone level measurement reveals the differences during seed development between seedless and seeded progeny. Based on both our results and previous studies of A. thaliana seed development, we generated network maps of grape seed-related DEGs, with particular reference to hormone balance, seed coat and endosperm development, and seed identity complexes.ConclusionIn summary, the major differences identified during seed development of seedless and seeded progeny were associated with hormone and epigenetic regulation, the development of the seed coat and endosperm, and the formation of seed identity complexes. Overall the data provides insights into the possible molecular mechanism controlling grape seed size, which is of great importance for both basic research and future translation applications in the grape industry.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-3193-1) contains supplementary material, which is available to authorized users.

How the truffle got its mate: insights from genetic structure in spontaneous and planted Mediterranean populations of Tuber melanosporum.

The life cycles and dispersal of edible fungi are still poorly known, thus limiting our understanding of their evolution and domestication. The prized Tuber melanosporum produces fruitbodies (fleshy organs where meiospores mature) gathered in natural, spontaneously inoculated forests or harvested in plantations of nursery-inoculated trees. Yet, how fruitbodies are formed remains unclear, thus limiting yields, and how current domestication attempts affect population genetic structure is overlooked. Fruitbodies result from mating between two haploid individuals: the maternal parent forms the flesh and the meiospores, while the paternal parent only contributes to the meiospores. We analyzed the genetic diversity of T.melanosporum comparatively in spontaneous forests vs. plantations, using SSR polymorphism of 950 samples from South-East France. All populations displayed strong genetic isolation by distance at the metric scale, possibly due to animal dispersal, meiospore persistence in soil, and/or exclusion of unrelated individuals by vegetative incompatibility. High inbreeding was consistently found, suggesting that parents often develop from meiospores produced by the same fruitbody. Unlike maternal genotypes, paternal mycelia contributed to few fruitbodies each, did not persist over years, and were undetectable on tree mycorrhizae. Thus, we postulate that germlings from the soil spore bank act as paternal partners. Paternal genetic diversity and outbreeding were higher in plantations than in spontaneous truffle-grounds, perhaps because truffle growers disperse fruitbodies to maintain inoculation in plantations. However, planted and spontaneous populations were not genetically isolated, so that T.melanosporum illustrates an early step of domestication where genetic structure remains little affected.

Molecular Breeding of Rice Restorer Lines and Hybrids for Brown Planthopper (BPH) Resistance Using the Bph14 and Bph15 Genes.

BackgroundThe development of hybrid rice is a practical approach for increasing rice production. However, the brown planthopper (BPH), Nilaparvata lugens Stål, causes severe yield loss of rice (Oryza sativa L.) and can threaten food security. Therefore, breeding hybrid rice resistant to BPH is the most effective and economical strategy to maintain high and stable production. Fortunately, numerous BPH resistance genes have been identified, and abundant linkage markers are available for molecular marker-assisted selection (MAS) in breeding programs. Hence, we pyramided two BPH resistance genes, Bph14 and Bph15, into a susceptive CMS restorer line Huahui938 and its derived hybrids using MAS to improve the BPH resistance of hybrid rice.ResultsThree near-isogenic lines (NILs) with pyramided Bph14 and Bph15 were obtained by molecular marker-assisted backcross (MAB) and phenotypic selection. The genomic components of these NILs were detected using the whole-genome SNP (Single nucleotide polymorphism) array, RICE6K, suggesting that the recurrent parent genome (RPG) recovery of the NILs was 87.88, 87.70 and 86.62 %, respectively. BPH bioassays showed that the improved NILs and their derived hybrids carrying homozygous Bph14 and Bph15 were resistant to BPH. However, the hybrids with heterozygous Bph14 and Bph15 remained susceptible to BPH. The developed NILs showed no significant differences in major agronomic traits and rice qualities compared with the recurrent parent. Moreover, the improved hybrids derived from the NILs exhibited better agronomic performance and rice quality compared with the controls under natural field conditions.ConclusionsThis study demonstrates that it is essential to stack Bph14 and Bph15 into both the maternal and paternal parents for developing BPH-resistant hybrid rice varieties. The SNP array with abundant DNA markers is an efficient tool for analyzing the RPG recovery of progenies and can be used to monitor the donor segments in NILs, thus being extremely important for rice molecular breeding.

Integrated analysis of phenome, genome, and transcriptome of hybrid rice uncovered multiple heterosis-related loci for yield increase

Hybrid rice is the dominant form of rice planted in China, and its use has extended worldwide since the 1970s. It offers great yield advantages and has contributed greatly to the world's food security. However, the molecular mechanisms underlying heterosis have remained a mystery. In this study we integrated genetics and omics analyses to determine the candidate genes for yield heterosis in a model two-line rice hybrid system, Liang-you-pei 9 (LYP9) and its parents. Phenomics study revealed that the better parent heterosis (BPH) of yield in hybrid is not ascribed to BPH of all the yield components but is specific to the BPH of spikelet number per panicle (SPP) and paternal parent heterosis (PPH) of effective panicle number (EPN). Genetic analyses then identified multiple quantitative trait loci (QTLs) for these two components. Moreover, a number of differentially expressed genes and alleles in the hybrid were mapped by transcriptome profiling to the QTL regions as possible candidate genes. In parallel, a major QTL for yield heterosis, rice heterosis 8 (RH8), was found to be the DTH8/Ghd8/LHD1 gene. Based on the shared allelic heterozygosity of RH8 in many hybrid rice cultivars, a common mechanism for yield heterosis in the present commercial hybrid rice is proposed.

Natural hybridization between Torreya jackii and T. grandis (Taxaceae) in southeast China

AbstractThe recognition of natural hybridization can help to understand the origin and maintenance of biodiversity. Based on intermediate morphology and overlapped distribution, Torreya grandis var. jiulongshanensis Z. Y. Li, Z. C. Tang & N. Kang was regarded as a putative natural hybrid between T. jackii Chun and T. grandis Fort. ex Lindl. in southeast China. This study tested the hybridization origin of T. grandis var. jiulongshanensis using nuclear internal transcribed spacer (ITS) and cytoplasm (chloroplast rbcL and rpl16 and mitochondrial rps3) DNA sequences. The results showed that most heterozygous sites of nuclear ITS sequences in T. grandis var. jiulongshanensis showed additivity between T. jackii and T. grandis. Cloned ITS sequences of T. grandis var. jiulongshanensis separately clustered with T. jackii and T. grandis in the phylogenetic analyses. Meanwhile, all of chloroplast and mitochondrial haplotypes of T. grandis var. jiulongshanensis were identical to those of T. jackii, not T. grandis. On the chloroplast DNA phylogenetic trees, T. grandis var. jiulongshanensis were grouped into the clade of T. jackii. These results suggest that T. grandis var. jiulongshanensis is a natural hybrid between T. jackii (maternal parent) and T. grandis (paternal parent). This study also implies that T. grandis should be cultivated with caution near the sites of T. jackii, because the endangered status of the latter might be deteriorated due to hybridization.

Conditions that Impact Artificial Hybridization of Arachis hypogaea L.

ABSTRACT Modern farming is dependent on continual development of improved cultivars and efficient cultural management practice. In addition, dissecting genetic components of heritable traits also relies on the development of large mapping populations. Artificial hybridization is the critical initial step in these processes. Peanut is a self-pollinating crop with a typical yield of less than three seeds per flower; therefore, significant effort is required to produce sufficient hybrid seeds for subsequent trait selection and/or establishment of mapping populations. A study was conducted to evaluate the effect of multiple factors on the success rate of artificial hybridization assessed by transmission of molecular markers unique to the paternal parent. Multiple peanut genotypes were crossed with a breeding line homozygous for both high oleic acid and nematode resistance. The impacts of operator, pollination time, flower integrity, genotype and environment on hybridization were evaluated. Data indicated that operator, pollination time and environment significantly affected the success rate of peanut hybridization. Pods from runner type parental plants that contain hybrid seeds were more likely to contain single seeds than those derived from self-pollination. Hybrid seed loss due to seed rot and peg damage reduced yield. Improving hybridization success rate by increasing humidity, decreasing temperature, personnel training and greenhouse management is recommended.

Viola woosanensis, a recurrent spontaneous hybrid between V. ulleungdoensis and V. chaerophylloides (Violaceae) endemic to Ulleung Island, Korea.

Ulleung Island is an oceanic volcanic island in Korea, which has never been connected to the adjacent continent. Previous studies highlighted Ulleung Island as an excellent system to study the pattern and process of early stages of flowering plant evolutions on oceanic island. The predominant mode of speciation in flowering plants on Ulleung Island appears to be anagenesis. However, the potentially important role of hybrid speciation among incompletely reproductively isolated lineages cannot be ruled out. Viola woosanensis (Violaceae) is of purportedly hybrid origin between V. ulleungdoensis (i.e., formerly recognized as V. selkirkii in Ulleung Island) and V. chaerophylloides, based on morphology. To examine the origin of V. woosanensis, we sampled a total of 80 accessions, including V. woosanensis and its putative parental species and sequenced nrDNA ITS, and four highly variable chloroplast noncoding regions (trnL-trnF, rpl16 intron, atpF-atpH, and psbA-trnH). Representative species of Viola from Korea were also included in the phylogenetic analyses (maximum parsimony, maximum likelihood, and Bayesian inference). Additive polymorphic sites in the nrDNA ITS regions were confirmed by cloning amplicons from representative species. The molecular data strongly supported the hybrid origin of V. woosanensis, and the maternal and paternal parent were determined to be V. ulleungdoensis and V. chaerophylloides, respectively. The presence of two parental ribotypes in V. woosanensis (with the exception in one population) was confirmed by cloning, suggesting V. woosanensis is primarily the F1 generation. No trace of backcrossing and introgression with its parents was detected due to low fertility of hybrid species. We found a multiple and unidirectional hybrid origin of V. woosanensis. Additional studies are required to determine which factors contribute to asymmetric gene flow of Viola species in Ulleung Island.

Likely allopatric origins of Adiantum × meishanianum (Pteridaceae) through multiple hybridizations

AbstractAdiantum × meishanianum F. S. Hsu ex Y. C. Liu & W. L. Chiou was regarded as an endemic species in Meishan Village, Kaohsiung, Taiwan, China and a hybrid between A. malesianum Ghatak (the maternal parent) and a sexually reproducing diploid cryptic species of A. philippense L. (the paternal parent), as revealed by chloroplast and nuclear markers. However, morphological research revealed that A. × meishanianum is also disjunctively distributed in Yunnan and that its paternal parent is possibly A. menglianense Y. Y. Qian. Thus, this study aimed to confirm these findings by using two chloroplast regions and a low‐copy nuclear marker in DNA barcoding and phylogenetic analyses, spore measurement, and flow cytometry. Our results indicated that A. × meishanianum in Yunnan is triploid and abortive, the same as A. × meishanianum in Taiwan, and they both originated from the hybridization between the maternal parent of A. malesianum and the paternal parent of A. menglianense, but not A. philippense. In conclusion, A. × meishanianum probably originated from multiple hybridizations in Taiwan and Yunnan.

The association between the MAOA 2R genotype and delinquency over time among men: the interactive role of parental closeness and parental incarceration.

Using a panel of 6,001 males from the National Longitudinal Study of Adolescent and Adult Health, we examine potential moderation by paternal incarceration and parent-child closeness altering the relationship between the rare 2R MAOA genotype and delinquency. By jointly examining moderation patterns for both the mother and father with the transmission of the MAOA genotype from mother to son, we are able to make inferences about the specific genetic model that best explains these outcomes. In line with prior research, we find a direct relationship between the MAOA 2R genotype and delinquency, independent of parental incarceration and closeness. Examining moderation patterns, we find that delinquency risk for the 2R allele is buffered for males close to their biological or social father, but not their biological mother. We conclude that the 2R delinquency association is not due to passive gene-environment correlation but is best characterized as a social control gene-environment interaction.

RESPONSE OF LATE MATURITY MAIZE LINES AND HYBRIDS TO SOUTHERN CORN LEAF BLIGHT DISEASE CAUSED BY BIPOLARIS MAYDIS

To evaluate resistance of maize late maturity lines and hybrids to southern corn leaf blight disease (Bipolaris maydis), an experiment was performed in randomized complete block design with three replications in Karaj and Sari during 2013, using seventeen maize lines and hybrids. Artificial inoculation was carried out two times, first by injection of spore suspension into the whorls of the plants at 3-4 leaf stage, and the second by inoculation of infected sorghum seed with the pathogen into whorls by bazooka at 6-8 leaf stage. Disease severity on leaves of inoculated plants was scored one month after the second inoculation. The results of analysis of variance and means comparison indicated significant differences among lines and hybrids for disease severity. Among eight hybrids, only KSC 708 (A679 × K19) exhibited resistance response (R). Five lines were moderately resistant (MR) among them two commercial lines MO17 and K19 had disease severity less than 10%. Based on the results of this experiment, two latter lines were recognized as favourable sources of resistance to the disease. Line K19 is the paternal parent of hybrid KSC 708 (A679 × K19) which was resistant in this investigation.

Differential Sensitivity of Genetically Related Potato Cultivars to Treatments Designed to Alter Apical Dominance, Tuber Set and Size Distribution

The cultivar, Bondi, was selected from a cross between Ranger Russet (maternal parent) and Karaka and is currently being evaluated as a frozen processing cultivar. Relative to Ranger, Bondi produces vigorous foliar growth, low tuber set and high yields of large tubers that frequently exceed optimum size for seed and processing markets. We evaluated the relative efficacies of gibberellin (GA), cytokinin (benzyladenine (BA)) and seed aging for altering apical dominance, tuber set and size distribution of these genetically related cultivars. GA applied to cut seed prior to planting hastened emergence, reduced apical dominance, increased tuber set and decreased average tuber size; however, the optimal concentration to maximally shift tuber size distribution without decreasing marketable yield was 4–5-fold greater for Bondi than Ranger. BA marginally hastened plant emergence (Bondi) and decreased apical dominance (both cultivars) only when combined with GA, but had no further effects on tuber set, yields or tuber size distributions in either cultivar. Age-priming Ranger seed for 700 degree days (DD) at 32 °C during storage shifted the tuber size distribution to a much greater extent than 2 mg L−1 GA (optimal concentration) without reducing marketable yield. The combined age and GA treatment resulted in no further shift in size distribution for Ranger beyond that induced by the 700-DD treatment alone, but reduced the marketable yield by 9.6 MT ha−1. In contrast to GA, the mechanism by which age-priming altered tuber size distribution in Ranger could not be explained by effects on stem number/tuber set relationships alone. Bondi, however, exhibited an even greater shift toward smaller tubers with no reduction in yield with the combined 700-DD/GA (2 mg L−1) treatment, reflecting its decreased sensitivity to GA. Moreover, the shift in tuber size distribution induced by aging Bondi seed for 700 DD was approximately equal to that observed by treating seed with 8 mg L−1 GA (optimal concentration). The reduced sensitivity of Bondi to GA was likely inherited from its paternal parent Karaka, which displays similar morphological traits, including high yield of large tubers.

Confirmation of Single-Locus Sex Determination and Female Heterogamety in Willow Based on Linkage Analysis.

In this study, we constructed high-density genetic maps of Salix suchowensis and mapped the gender locus with an F1 pedigree. Genetic maps were separately constructed for the maternal and paternal parents by using amplified fragment length polymorphism (AFLP) markers and the pseudo-testcross strategy. The maternal map consisted of 20 linkage groups that spanned a genetic distance of 2333.3 cM; whereas the paternal map contained 21 linkage groups that covered 2260 cM. Based on the established genetic maps, it was found that the gender of willow was determined by a single locus on linkage group LG_03, and the female was the heterogametic gender. Aligned with mapped SSR markers, linkage group LG_03 was found to be associated with chromosome XV in willow. It is noteworthy that marker density in the vicinity of the gender locus was significantly higher than that expected by chance alone, which indicates severe recombination suppression around the gender locus. In conclusion, this study confirmed the findings on the single-locus sex determination and female heterogamety in willow. It also provided additional evidence that validated the previous studies, which found that different autosomes evolved into sex chromosomes between the sister genera of Salix (willow) and Populus (poplar).

Does paternal sterility impact on progeny germination and survivorship, case study in strawberries

Studies on the parental role on progeny performance have mostly focused on the maternal parent, while less attention was given to the paternal parent. This study investigated the impact of paternal pollen sterility (ranging from 3.1 – to 77.2%) on F1 seed germination and progeny survivorship in Fragaria (strawberry, Rosaceae) using controlled crosses. In crosses within F. vesca ssp. vesca the paternal pollen sterility was not correlated with F1 seed germination (N = 14, p > 0.074) and progeny survivorship (N = 14, p > 0. 0.710). Paternal sterility in crosses between F. vesca ssp. vesca and F. vesca ssp. monophylla did not affect on F1 seed germination (N = 7, p > 0.295) and progeny survivorship (N = 6, p > 0.812). Similarly, no correlation was found between father pollen sterility and F1 seed germination (N = 6, p > 0.924) and progeny survivorship (N = 6, p > 0.215) in crosses between F. vesca ssp. americana and F. vesca ssp. vesca. Furthermore, crossing different maternal plants by pollen of the same paternal plant in all three cross types produced progeny with variable levels of F1 seed germination and survivorship. These results indicate the crucial role of maternal plant on progeny performance and support the general idea of the importance of maternal rather than paternal parent on progeny performance.

Development and application of marker-assisted reverse breeding using hybrid maize germplasm

Humankind has been through different periods of agricultural improvement aiming at enhancing our food supply and the performance of food crops. In recent years, whole genome sequencing and deep understanding of genetic and epigenetic mechanisms have facilitated new plant breeding approaches to meet the challenge of growing population, dwindling resources, and changing climate. Here we proposed a simple and fast molecular breeding method, marker-assisted reverse breeding (MARB), which will revert any maize hybrid into inbred lines with any level of required similarity to its original parent lines. Since all the pericarp DNA of a hybrid is from the maternal parent, whereas one half of the embryo DNA is from the maternal parent and the other half from the paternal parent, so we firstly extract DNA from seed embryo and pericarp of a selected elite hybrid separately and then we derived the genotypes of the two parents with high-density single nucleotide polymorphism (SNP) chips. The following marker-assisted selection was performed based on an Illumina low-density SNP chip designed with 192 SNPs polymorphic between the two parental genotypes, which were uniformly distributed on 10 maize chromosomes. This method has the advantages of fast speed, fixed heterotic mode, and quick recovery of beneficial parental genotypes compared to traditional pedigree breeding using elite hybrids. Meanwhile, MARB has the advantage of not requiring sophisticated transformation and double haploid (DH) technologies over RNA interference (RNAi)-mediated reverse breeding. In addition, MARB can also be used with feed corn harvested from big farms, which is often similar to F2 populations, and the relevant transgenes in the population can be eliminated by marker-assisted selection. As a result, the whole global commercial maize hybrids can be utilized as germplasm for breeding with MARB technology. Starting with an F2 population derived from an elite hybrid, our experiment indicates that with three cycles of marker-assisted selection, selected lines could recover over 80% of the parental genotypes and associated beneficial genes in a fixed heterotic mode. The success application of MARB in maize suggests that this technology is applicable to any hybrid crop to breed new inbreds with improved hybrid performance but the same heterotic mode. As chip technology becomes cheap, it would be expected that polymorphism screening and following marker-assisted selection could be done with one all-purpose high density chip. Several issues associated with MARB were discussed, including its rationale, efficiency and advantages, along with food/feed and environmental safety issues and applications of MARB in variety protection and marker-assisted plant breeding.

A maize bundle sheath defective mutation mapped on chromosome 1 between SSR markers umc1395 and umc1603

The bsd-pg (bundle sheath defective pale green) mutant is a novel maize mutation, controlled by a single recessive gene, which was isolated from offspring of maize plantlets regenerated from tissue callus of the maize inbred line 501. The characterization was that the biogenesis and development of the chloroplasts was mainly interfered in bundle sheath cells rather than in mesophyll cells. For mapping the bsd-pg, an F2 population was derived from a cross between the mutant bsd-pg and an inbred line Xianzao 17. Using specific locus amplified fragment sequencing (SLAF-Seq) technology, a total of 5 783 polymorphic SLAFs were analysed with 1 771 homozygous alleles between maternal and paternal parents. There were 49 SLAFs, which had a ratio of paternal to maternal alleles of 2:1 in bulked normal lines, and three trait-related candidate regions were obtained on chromosome 1 with a size of 3.945 Mb. For the fine mapping, new simple sequence repeats (SSRs) markers were designed by utilizing information of the B73 genome and the candidate regions were localized a size of 850 934 bp on chromosome 1 between umc1603 and umc1395, including 35 candidate genes. These results provide a foundation for the cloning of bsd-pg by map-based strategy, which is essential for revealing the functional differentiation and coordination of the two cell types, and helps to elucidate a comprehensive understanding of the C4 photosynthesis pathway and related processes in maize leaves.

Pollen movement in a Malus sylvestris population and conclusions for conservation measures

Knowledge of pollen movement and frequency of interspecific hybridization in fragmented populations of rare species is a prerequisite for the implementation of conservation measures. In a large-scale study area (14,000 hectares) we analysed 297 Malus sylvestris trees with nine nuclear microsatellite markers. After open pollination of 564 offspring from 51 mother trees located in seven harvesting sites were investigated and genetic paternity analysis was performed. The paternal parent was identified for 213 offspring and the pollen dispersal distances between mother and pollen source were calculated. A large proportion of detected pollination events (42.4%) were observed within a radius of 50 m of the mother tree. The comparison of different tree densities indicated that with decreasing density the pollen dispersal distances increase. We observed pollination over long distances with a maximum of 10.7 km which is probably one of the reasons for a low spatial genetic structure within the M. sylvestris population and a stable genetic diversity in the offspring. Incorporating microsatellite data of 21 apple cultivars, a hybridization frequency of nearly 8% was determined. With decreasing tree density the number of hybridization events increased. Based on the results of our study an enhancement of the density of existing M. sylvestris populations is recommend to reduce the likelihood of hybridization. The production of young plants originated from seeds collected after open pollination is not advisable. Instead of that the seedlings for further reintroduction measures should be produced by controlled crossings in seed orchards to ensure ‘true type’ M. sylvestris individuals.

Genetic diversity and parentage analysis of aspen demes

Genetic diversity and genealogical relationships among individuals of eight aspen demes in a common garden experiment were studied using microsatellite (SSR) and amplified fragment length polymorphism (AFLP) markers. Moderate to high levels of genetic diversity were observed within all demes for the SSR and AFLP markers. The Shannon index for the AFLP markers was positively and significantly correlated with the average observed heterozygosity for the SSR markers across the demes. Comparative analysis of the numbers of the full-sibling groups inferred by different algorithms suggested that the 2-allele algorithm was more accurate than the other methods used in the study. However, in general, significant correlations were found in the numbers of the full-sibling groups inferred by some other algorithms, such as a heuristic algorithm, the 2-allele algorithm, and the Simpson, modified Simpson and pairwise score algorithms. Among demes, the USA and Swiss demes had the highest and lowest numbers, respectively, of full-sibling groups. This combined approach for sibship reconstruction can also be applied to infer the number of paternal or maternal parents in forest tree plantations when no parental information is available; this approach can improve our understanding of family structure and the extent of genetic diversity within forest tree plantations when no diversity, origin, or parental genotypes information is available.

Morphological and molecular identification of natural hybridization between Begonia hemsleyana and B. macrotoma

Several plants of a putative hybrid of Begonia were found in southern Yunnan of China during a field survey. They were preliminarily identified as the offspring of a natural hybrid between Begonia hemsleyana as the maternal parent and B. macrotoma as the paternal parent based on the following reasons: the putative hybrid grows sympatrically with B. hemsleyana and B. macrotoma, but more closely to the former; it shows some intermediate morphological characteristics between parents; and the flowering time of parents overlaps, at least partially. Molecular information of internal transcribed spacer (ITS), chloroplast spacer ndhF-rpl32 and SSR markers supported our hypothesis of the natural hybrid between B. hemsleyana (♀) and B. macrotoma (♂). The hybrid should be the first generation (F1) and was named as Begonia × dashuigouensis D.K. Tian based on the name of place where it was discovered.

Genetic Variation and Heritability Estimates for Bunch Yield, Bunch Components and Vegetative Traits in Oil Palm Interspecific Hybrids

Progeny testing of oil palm interspecific hybrids was conducted in four trials in Kluang, Ulu Paka, Teluk Intan and Carey Island, Malaysia. The interspecific hybrids (O  P) were created according to the North Carolina Model I (NCM I) mating design, using Elaeis oleifera (O) and Elaeis guineensis var. pisifera (P) as the maternal and paternal parents, respectively. Differences among O, P and O-within-P were determined by the performance (bunch yield, components and vegetative traits) of the progenies. There were significant differences among P for fresh fruit bunch (FFB) yield, bunch number (BN) and average bunch weight (ABW) in Kluang, Ulu Paka and Teluk Intan, but not in Carey Island. FFB yield was generally higher on coastal soils (Teluk Intan and Carey Island) than inland soils (Kluang and Ulu Paka). Heritability was calculated based on the intraclass correlation. Heritability estimates for these three yield components were variable, depending on the breeding material and environment in which the materials were tested. Fruit to bunch (F/B) and oil to bunch (O/B) of parthenocarpic fruits were important in determining the overall O/B of the interspecific hybrids. The O  P hybrids in Kluang showed the lowest height increment with only a mean of 14.0 cm/year, whereas in Ulu Paka and Teluk Intan, the values were higher at 24.0 cm/year and 25.0 cm/year, respectively. The study showed that the FFB yields of oil palm interspecific hybrids performed better in coastal soils than inland soils.