Mitochondrial DNA diversity in wild boar from the Primorsky Krai Region (East Russia)

We have studied the cytochrome B gene and control region DNA variability in 14 wild boars from the Primorsky Region, in the far east corner of Russia. Variability was low (π = 0.00248 overall) compared with the usual estimates in these loci, indicating that this is a rather closed population. Seven haplotypes were found, and one was identical to a Chinese wild boar. Phylogeographically, the sequences clustered among several Asian clades, primarily Chinese domestic pigs and Japanese and Chinese wild boars, and are positioned within the D2 clade reported by Larson et al. [ Science 307 , 2005; 1618 ]. Although North Korean pigs should be studied, our data suggest that the Primorsky mtDNA signature is absent from domestic pigs. Sequences are available through GenBank identifiers HM010461 – HM010488 .     

Worldwide genetic relationships of pigs as inferred from X chromosome SNPs

The phylogeography of the porcine X chromosome has not been studied despite the unique characteristics of this chromosome. Here, we genotyped 59 single nucleotide polymorphisms (SNPs) in 312 pigs from around the world, representing 39 domestic breeds and wild boars in 30 countries. Overall, widespread commercial breeds showed the highest heterozygosity values, followed by African and American populations. Structuring, as inferred from F_ST and analysis of molecular variance, was consistently larger in the non‐pseudoautosomal (NPAR) than in the pseudoautosomal regions (PAR). Our results show that genetic relationships between populations can vary widely between the NPAR and the PAR, underscoring the fact that their genetic trajectories can be quite different. NPAR showed an increased commercial‐like genetic component relative to the PAR, probably because human selection processes to obtain individuals with high productive parameters were mediated by introgressing boars rather than sows.     

Stigmatic pollen delivery by flies and bees: Methods comparing multiple species within a pollinator community

A wide variety of insect species provide pollination services in natural and agricultural ecosystems, but in order to quantify their contribution it is necessary to evaluate their effectiveness. An important component of this is to determine their ability to transfer pollen to stigmas which typically requires observers to wait for insects to visit focal flowers (static approach); a time-consuming process not amenable to obtaining measures for pollinating species of low local abundance. An alternative method (active approach) is to detach test flowers and present them to the targeted flower visitor. This offers a number of advantages (e.g. increased speed and flexibility), but may alter insect behaviour. We compared pollen deposition within flowering onion crops using three bee (Apoidea) and three fly (Diptera) species. The two approaches resulted in similar numbers of pollen grains being deposited onto stigmas for each insect species, thereby supporting the validity of the active as an alternative to the static approach in our test crop. The ability to rapidly assess stigmatic pollen deposition of a broad range of insects using the active approach can greatly assist assessments of pollinator contribution within plant pollinator assemblages.     

Wheat storage proteins: glutenin diversity in wild emmer,Triticum dicoccoides,in Israel and Turkey. 2. DNA diversity detected by PCR

Germplasm of Triticum dicoccoides collected from different environments in Israel was evaluated by using the PCR as a molecular marker. Two pairs of primers were used in the PCR in amplifying the DNA tracts coding the high-and low-molecular-weight glutenin subunits. Analyses reveal great variability within and between populations indicating the high values of this germplasm for future breeding programs to improve the protein quality in wheat.     

Secondary succession of weed communities in lowland habitats of Taiwan in relation to the introduction of wild-rice (Oryza perennis) populations

Wild-rice (Oryza perennis Moench) populations were introduced into abandoned lowland fields (and a ditch) at five sites in Taiwan. The weeds arising after clearance and tillage of the fields were observed with regard to various attributes of the community during three years. Among a total of 84 identified species, Leersia hexandra had the highest relative frequency. With secondary succession, the percentage biomass of perennial species, particularly of grasses, gradually increased and the dominance index (1-H′/H′ _max) also increased. Species present in the buried seed pool in soil samples showed a different pattern of successional changes. With species classified into grass, sedge, and dicot groups and their percentage of biomass data compared with corresponding data for the density of plants from buried seeds, a negative correlation was found which suggested differences in behavior among the plant groups. Experiments on the effects of weeding and inundation suggested that the niches of Oryza perennis and of Leersia hexandra largely overlap, and differed from that of Panicum repens. The wild-rice populations declined as Leersia dominated. This relationship was demonstrated by principal component analysis and standard partial regression analysis of the data.     

A genome-wide search for wild-species alleles that increase horticultural yield of processing tomatoes

To identify QTLs associated with horticultural yield it is necessary to conduct replicated plot trials of the tested genotypes. The first step in the utilization of an introgression-line (IL) population of Lycopersicon pennellii in a processing-tomato variety (M82) for mapping such QTLs was to screen 51 ILs in a non-replicated plot trial. The results of this survey were compared to those obtained in a replicated trial of the same genotypes grown as single plants at wide spacing. Fruit characteristics were similar between the two stands, but yield was generally different. Eight lines that outperformed the control in the plot survey were subjected to detailed analysis in the following year. The effects of these introgressions, measured on single plants, were reproducible relative to the previous year's results. In a replicated plot trial of these ILs and their hybrids involving two genetic backgrounds, the product of yield and total soluble solids (horticultural yield) in seven of the eight hybrids was 7–13% higher than that of their nearly isogenic controls. The results revealed a consistent trend in the interaction between introgression effects and genetic background. Combining the two introgressions with the largest contribution to horticultural yield in plots resulted in a 20% increase relative to the control in the third year. This research highlights the potential of wild germ plasm for yield improvement and the ability of nearly isogenic populations to achieve this goal.     

Inter- and intra-specific distribution of Stowaway transposable elements in AA-genome species of wild rice

The presence or absence of miniature inverted-repeat transposable elements (MITEs) that belong to Stowaway family was analyzed at three loci, two of which are newly identified, in five wild rice species having the AA genome. The pattern of the presence or absence of MITEs was found to be highly associated with speciation in this plant group. In Oryza rufipogon, the pattern was also associated with differentiation into annual or perennial ecotypes. These results suggest either that gene flow has been highly restricted between different species, as well as between different ecotypes of O. rufipogon after they were differentiated, or that loci with or without MITEs have been selected in nature together with the linked genes that are responsible for adaptation to environments. In addition, a very low polymorphism with regard to the presence or absence of MITEs within each species or each ecotype suggests that the frequency of transposition of MITEs is very low, assuming that the loci that contain MITEs are free from selection pressure. Received: 30 October 1999 / Accepted: 2 December 1999     

Quantitative variation in the kernel proteins among 841 accessions of Triticum dicoccoides estimated by SDS-PAGE

Summary The relative proportion and amount of proteins in five defined molecular weight (MW) regions (A1=above 71,000=71K, A2=71K–49K, A3=49K–31K, A4=31K–20K, A5=20K and less) were estimated by densitometric analyses of the amount of dye bound by kernel proteins (Fullington et al. 1980) of Triticum dicoccoides SDS-PAGE gels. These MW regions roughly correspond to the wheat protein solubility classes (Cole et al. 1981; Fullington et al. 1983). One purpose of the study was to select accessions whose seed proteins bind relatively high amounts of dye in the glutenin and albumin globulin regions. These accessions will be used for further in-depth studies as possible candidate donors of genes to improve the baking and nutritional quality of wheat. Marked differences in the quantitative relationships were found among the proteins in the five MW regions. Coefficients of variation (CV's) for the highest peak (i.e., most abundant protein) MW in different protein MW regions were similar for A1, A2 and A3, at 11.4, 11.7, and 11.1%, respectively, but only 4.1 for A4, and 10.6% for region A5. The CV for the highest peak MW overall was 29.8. Accession BP0649, for example, had over 44% of its protein in region A5, whereas BP0566 (lowest among the top 10%) had only 21.4% of its protein in that region. Over 37% of the proteins of accessions BP0649 and 0001 to 0005 was in region A5. At least 84 accessions with the highest amount of protein in region A5, and 13 accessions with more protein in region A1 than Chinese Spring may merit further evaluation as possible protein gene donors. High amounts of protein in A1 may be of importance in bread-baking quality, and in A4 and A5 for high lysine wheat. Accessions in both extremes were selected to test these hypotheses. All accessions are now or will be available in the USDA Wheat Collection.Scientific Paper No. 7092. College of Agriculture Research Center, Washington State University, Pullman, Project No. 1568. This work was supported in part by the U.S.-Israel Binational Agricultural Research and Development Fund (BARD)     

A biosystematic study of theOryza meyeriana complex (Poaceae)

To determine the taxonomic status and to clarify the biosystematic relationships of wild rice species, i.e.,Oryza granulata andO. meyeriana in theO. meyeriana complex (Poaceae), a series of intraspecific and interspecific hybridization experiments, genomic analyses through meiotic pairing, and morphological studies were conducted. Hybridization results demonstrate comparatively high crossability with about 34–39% of seed set, and very limited reproductive isolation betweenO. granulata andO. meyeriana. Chromosome pairing in the parental species and their F₁ hybrids indicate very high genomic affinity between the two taxa. Morphological analyses of the parental accessions and their intra- and interspecific hybrids show a large variation among the samples included, but no appreciable grouping was observed. The traditionally used character, i.e., spikelet length, does not contribute significantly to the grouping of the samples included. Based on the facts that the two taxa have negligible reproductive barriers and share almost identical genomes, the authors believe thatO. granulata andO. meyeriana do not warrant separate taxonomic status, and recommend that they be combined asOryza granulata.     

Maackiain in Cicer bijugum Rech. f. associated with resistance to Botrytis grey mould

Resistance in Cicer bijugum Rech. f. a wild relative of chickpea, to Botrytis grey mould (BGM), caused by Botrytis cinerea Pers., was shown to be associated with high concentrations of maackiain when compared to three susceptible species. The two BGM resistant accessions of C. bijugum contained between 200 and 300 μg maackiain g⁻¹ of foliage whereas the BGM susceptible species C. arietinum, C. echinospermum and C. reticulatum contained less than 70 μg g⁻¹. Furthermore, the concentration of maackiain increased to more than 400 μg g⁻¹ in the resistant wild species after being inoculated with the pathogen whereas no significant increase was recorded in the susceptible species. The germination of spores of Botrytis cinerea, treated with maackiain, was inhibited in a dose dependent manner; less than 10% of spores germinated when treated with 500 μg ml⁻¹. The data indicate that maackiain may be an important component in BGM resistance in the wild chickpea C. bijugum and that the resistance is enhanced in the presence of the pathogen.