Multievent: an extension of multistate capture-recapture models to uncertain states

Capture-recapture models were originally developed to account for encounter probabilities that are less than 1 in free-ranging animal populations. Nowadays, these models can deal with the movement of animals between different locations and are also used to study transitions between different states. However, their use to estimate transitions between states does not account for uncertainty in state assignment. I present the extension of multievent models, which does incorporate this uncertainty. Multievent models belong to the family of hidden Markov models. I also show in this article that the memory model, in which the next state or location is influenced by the previous state occupied, can be fully treated within the framework of multievent models.     

Toxin-based in-vitro selection and its potential application to date palm for resistance to the bayoud Fusarium wilt

Date palm (Phoenix dactylifera L.) is qualified as a 'tree' of great ecological and socio-economical importance in desert oases. Unfortunately, it is being decimated, especially in Morocco and Algeria, by a fusariosis wilt called bayoud and caused by Fusarium oxysporum f. sp. albedinis (Fao). Controlling this disease requires the implementation of an integrated management program. Breeding for resistance is one of the most promising component strategies of this program. Few naturally resistant cultivars with a mediocre fruit quality (dates) are known. Conventional and non-conventional methods are under development and have to use the simplest and easiest methods to screen for resistant individuals. The use of pathogen toxins as selective agents at the tissue culture step might be a source of variability that can lead to the selection of individuals with suitable levels of resistance to the toxin and/or to the pathogen among the genetic material available. Foa produces toxins such as fusaric, succinic, 3-phenyl lactic acids and their derivatives, marasmins and peptidic toxins. These toxins can be used bulked or separately as selective agents. The aim of this contribution was to give a brief overview on toxins and their use as a mean to select resistant lines and to initiate a discussion about the potential use of this approach for the date palm-Foa pathosystem. This review does not pretend to be comprehensive or exhaustive and was prepared mainly to highlight the potential use of Foa toxins for selecting date palm individuals with a suitable resistance level to bayoud using toxin-based selective media.     

Exploring the relationship between parental relatedness and male reproductive success in the Antarctic fur seal Arctocephalus gazella

Recent genetic studies of natural populations have shown that heterozygosity and other genetic estimates of parental relatedness correlate with a wide variety of fitness traits, from juvenile survival and parasite resistance to male reproductive success. Many of these traits involve health and survival, where the underlying mechanism may involve changes in the effectiveness of the immune system. However, for traits such as reproductive success, the likely mechanisms remain less obvious. In this paper, we examine the relationship between heterozygosity and a range of traits that contribute to male reproductive success, including time spent on territories and competitiveness. Our analysis is based on observational and genetic data from eight consecutive breeding seasons at a colony of the Antarctic fur seal, Arctocephalus gazella. Overall, male reproductive success was found to correlate strongly with internal relatedness (IR, a form of heterozygosity). When different components of success were analyzed, we found that IR correlates independently with reproductive longevity, time spent ashore, and competitive ability per unit mating opportunity on the study beach, with more heterozygous males being more successful. Behavioral observations were sufficiently detailed to allow examination of how daily mean IR values for males present on the beach varied within seasons and from year to year. Again, significant variation was found both among and within seasons, with more homozygous males appearing less able to hold territories in poor seasons when pup production is low and, within a season, at both the start of the season and to some extent around the peak of female estrus. Finally, we tested whether the benefits of high heterozygosity are due mainly to a genomewide effect (e.g. inbreeding depression) or to single locus heterosis by asking whether the relationship between IR and male success was robust to the removal of any single locus or to any pair of loci. Since the relationship remained significant in all cases, we favor a multilocus explanation for the effects we report.     

Construction of a linkage map of Lentinula edodes (shiitake) with the HEGS (high-efficiency genome scanning) system: use of versatile AFLP and PCR-based gene markers

An improved linkage map of Lentinula edodes (shiitake) was constructed with an HEGS (high-efficiency genome scanning) system. Two hundred twenty-one HEGS-derived amplified fragment length polymorphism (AFLP-H) markers and 21 gene markers were developed and combined with 203 previously developed sequencer-derived AFLP markers (AFLP-S markers) and 3 mating factor loci (A, Bα, and Bβ) to construct a comprehensive linkage analysis. As a result, a novel linkage map with 166 markers including 2 mating factors (A and B), 10 HEGS-derived gene markers, 72 AFLP-H markers, and 82 AFLP-S markers was obtained. Of the total 448 markers, 273 could not be located on a linear map and thus were assigned to linkage groups as accessory markers. The map covers a total length of 1398.4 centimorgans (cM) with an average marker interval distance of 8.4 cM. The map consists of 11 linkage groups (LGs) in agreement with our previous map, and 7 LGs among them were found to contain branched linkages, which may be the result of reciprocal translocations representing dynamic reorganization of the shiitake genome. The previously reported linkage map was improved in terms of number of markers, marker density, linear order of markers, and total map length. Contribution no. 384 of the Tottori Mycological Institute     

河北唐海湿地四种鹭的种群动态和繁殖空间生态位

2004年8月—2005年7月对河北唐海湿地夜鹭(Nycticoraxnycticorax)、白鹭(Egtettagarzetta)、池鹭(Ardeolabacchus)、大白鹭(Casmerodiusalbus)的种群动态和繁殖行为进行了观察,并对巢群关系进行了研究。统计了4种鹭垂直和水平巢位的巢密度,计算了不同种鹭巢的生态位重叠、生态位宽度值。结果4种鹭在唐海数量最多月份为4—9月,最大量达到了近5800只。共有Ⅰ、Ⅱ两个巢区,迁来Ⅱ区时间较Ⅰ区晚半个月左右。除池鹭外,3种鹭之间均有争巢现象,后期趋于稳定。迫于密度压力和竞争,部分白鹭和池鹭取食范围较广。除大白鹭外,其他3种鹭同种间均有混交现象。在混巢区,夜鹭迁来最早,数量最大,为优势种,多数占据中心区的顶巢;大白鹭数量最少,亦占据中心区的顶巢;白鹭迁来较晚,占据中位巢;池鹭迁来最晚,数量较白鹭少,多数在边缘区单独筑巢,少数在中心区占下位巢。白鹭巢的垂直生态位最宽;夜鹭巢的水平生态位最宽;池鹭巢的综合空间生态位最宽。池鹭和夜鹭巢位的空间格局最为相似,池鹭和白鹭的生态位重叠较大。夜鹭的数量最多、大白鹭的个体最大,导致其处于优势;白鹭和池鹭数量少、个体小,导致其处于劣势。唐海湿地内丰富的食物和适宜的林带是鹭鸟密度较大的主要原因。此外,鹭类只筑巢在散布的、双行杨树林带均高为22m以上区域,是该地鹭类巢区的主要特点。     

Gynodioecy to dioecy: are we there yet?

Background

The ‘gynodioecy–dioecy pathway’ is considered to be one of the most important evolutionary routes from hermaphroditism to separate sexes (dioecy). Despite a large accumulation of evidence for female seed fertility advantages in gynodioecious species (females and hermaphrodites coexist) in support of the first step in the gynodioecy–dioecy pathway, we still have very little evidence for the second step, i.e. the transition from gynodioecy to dioecy.

Scope

We review the literature to evaluate whether basic predictions by theory are supported. To establish whether females'' seed fertility advantage and frequencies are sufficient to favour the invasion of males, we review these for species along the gynodioecy–dioecy pathway published in the last 5 years. We then review the empirical evidence for predictions deriving from the second step, i.e. hermaphrodites'' male fertility increases with female frequency, selection favours greater male fertility in hermaphrodites in gynodioecious species, and, where males and hermaphrodites coexist with females (subdioecy), males have greater male fertility than hermaphrodites. We review how genetic control and certain ecological features (pollen limitation, selfing, plasticity in sex expression and antagonists) influence the trajectory of a population along the gynodioecy–dioecy pathway.

Conclusions

Females tend to have greater seed fertility advantages over hermaphrodites where the two coexist, and this advantage is positively correlated with female frequency across species, as predicted by theory. A limited number of studies in subdioecious species have demonstrated that males have an advantage over hermaphrodites, as also predicted by theory. However, less evidence exists for phenotypic selection to increase male traits of hermaphrodites or for increasing male function of hermaphrodites in populations with high female frequency. A few key case studies underline the importance of examining multiple components of male fertility and the roles of pollen limitation, selfing and plasticity, when evaluating advantages. We conclude that we do not yet have a full understanding of the transition from gynodioecy to dioecy.     

Floral features,pollination biology and breeding system of Chloraea membranacea Lindl. (Orchidaceae: Chloraeinae)

Background and Aims

The pollination biology of very few Chloraeinae orchids has been studied to date, and most of these studies have focused on breeding systems and fruiting success. Chloraea membranacea Lindl. is one of the few non-Andean species in this group, and the aim of the present contribution is to elucidate the pollination biology, functional floral morphology and breeding system in native populations of this species from Argentina (Buenos Aires) and Brazil (Rio Grande do Sul State).

Methods

Floral features were examined using light microscopy, and scanning and transmission electron microscopy. The breeding system was studied by means of controlled pollinations applied to plants, either bagged in the field or cultivated in a glasshouse. Pollination observations were made on natural populations, and pollinator behaviour was recorded by means of photography and video.

Key Results

Both Argentinean and Brazilian plants were very consistent regarding all studied features. Flowers are nectarless but scented and anatomical analysis indicates that the dark, clavate projections on the adaxial labellar surface are osmophores (scent-producing glands). The plants are self-compatible but pollinator-dependent. The fruit-set obtained through cross-pollination and manual self-pollination was almost identical. The main pollinators are male and female Halictidae bees that withdraw the pollinarium when leaving the flower. Remarkably, the bees tend to visit more than one flower per inflorescence, thus promoting self-pollination (geitonogamy). Fruiting success in Brazilian plants reached 60·78 % in 2010 and 46 % in 2011. Some pollinarium-laden female bees were observed transferring pollen from the carried pollinarium to their hind legs. The use of pollen by pollinators is a rare record for Orchidaceae in general.

Conclusions

Chloraea membrancea is pollinated by deceit. Together, self-compatibility, pollinarium texture, pollinator abundance and behaviour may account for the observed high fruiting success. It is suggested that a reappraisal and re-analysis of important flower features in Chloraeinae orchids is necessary.     

Floral morphology and reproductive biology of Dendrobium jiajiangense (Orchidaceae) in Mt. Fotang,southwestern China

The relationships between floral morphology and the particular pollinator, flower shelter function and reproductive success as well as details of the breeding system of Dendrobium jiajiangense were investigated at Fotang Mountains in Jiajiang County, Sichuan Province, China. D. jiajiangense is pollinator-specific, being pollinated by Andrena parvula. There exists considerable mechanical fit between the floral morphology of D. jiajiangense and A. parvula. Importantly, A. parvula uses D. jiajiangense flowers as shelter both during rainy weather and at night during sunny weather. This significantly increase the pollination success of D. jiajiangens. D. jiajiangense is self-compatible but pollinator-dependent for fruit set. Fruit set of D. jiajiangens was 100% after hand-self-pollination, but seed viability was normally greatly reduced.