Fertility variation among individuals in natural stands of Acacia leucophloea

Female, male and total fertility variations were estimated in a base population and a seed orchard derived from the base population in Pinus brutia. Relative status number for gametes (female and male contribution) and zygotes (average of female and male contribution) were estimated based on the fertility variation. Average female and male strobilus production were 229.1 and 1003.3 in the base population, and 98.9 and 244.9 in the seed orchard for combined years, respectively. Positive and significant correlations were found between female and male strobilus production in both base population and seed orchard. The male fertility variation was higher than female fertility variation in the seed orchard, while female fertility variation was higher than male fertility variation in the base population. Coefficients of variations in female and male strobilus production were 0.721 and 0.696 in the base population, and 0.403 and 1.110 in the seed orchard for combined years, respectively. Total fertility variation was 1.41 in the base population and 1.40 in the seed orchard for combined years. The relative status numbers estimated based on the total fertility were 70% of census number in the base population, and 71% in the seed orchard for combined years.

There could be many environmental and biological impacts such as edaphic, geographic, climatic, age, tree structure and population on morphological, physiological and genetically seed quality in plant species. Gene diversity is an important mirror of genetically seed quality. Gene diversity in seed crops were estimated based on female and male strobili productions of fifty trees (N) randomly chosen from each population sampled over an altitudinal range as low (1200-400 meters ≤ altitude), middle (1400 m < altitude ≤ 1600 m), high (1600 m < altitude ≤ 1800 m), and very high (1800 m < altitude) in Taurus cedar also known as cedar of Lebanon (Cedrus libani A. Rich.) for two consecutive years (2021&2022). The variation in strobilus production was subjected to estimation of female and male fertility variation. The total fertility variation (Ψ) was estimated from the female and male fertility variation. Impacts of some growth characteristics (tree height and diameter at breast height) on strobili productions were also investigated. Strobili productions varied among the populations and individuals within population, and between years. The differences for populations and years were also found for coefficient of variations which were mirror of fertility variation of the strobili productions. Tree height and diameter at breast height seemed more reasonable predictor than age for number of strobili. Fertility variations of female parents were generally higher than that of male in both years. First year showed generally higher parental variations in individual populations. Gene diversity (GD=1-0.5Ψ/N) ranged from 0.967 to 0.974 for the populations and years. The loss of highest gene diversity was 0.004 in low population (0.967 & 0.971) between years. Results of the study indicated that altitudinal gene diversity of seed crop could be used to produce genetically quality seed and their grading. Moreover, data sets can be used to fill the Forest Landscape Restoration library (FLR-Library).

Reproductive output and fertility variation in teak were evaluated in five study sites in Western Ghats region of southern India. In four seed production areas (SPA1-4)) and a natural population (NAT) plots with 100 trees were investigated. The 40-year-old seed production areas are located in high rainfall (>2,500 mm) sites in Kerala state and the natural stand is at a drier location in Tamil Nadu. Fruit production per tree was rather high in the natural stand (1500) and quite variable in the seed production areas. SPA 4, located far south from the other sites, had the highest fruit production (almost twice that in the other study sites), high relative population size (Nr = 0.5) and predicted low genetic drift in two consecutive years. Fecundity was very low in SPAs 2 & 3 (200 fruits per tree). Reproductive output was similar in successive years except SPA 1, where the fruit production in the first year was almost five times that in the second year. Fertility variation (computed as sibling coefficient, Ψ) was in general higher in NAT and hence the relative population size was lower than in SPAs. The variation in female fertility in the natural stand was, somewhat surprisingly, similar to that in the seed production areas, while the male fertility variation was higher. In the seed production areas the male fertility variation was lower or similar to the female fertility variation. The fertility variation, Ψ was on average around 3 and correspondingly the relative effective population size, Nr = 0.36 and the variance effective number around 60. Selection for tree diameter would improve predicted diversity of the seed crop as it was positively correlated with reproductive output and negatively correlated with fertility variation among trees.

Fertility is a major component of fitness but its genetic architecture remains poorly understood. Using a full diallel cross of 50 Drosophila Genetic Reference Panel inbred lines with whole genome sequences, we found substantial genetic variation in fertility largely attributable to females. We mapped genes associated with variation in female fertility by genome-wide association analysis of common variants in the fly genome. Validation of candidate genes by RNAi knockdown confirmed the role of the dopamine 2-like receptor (Dop2R) in promoting egg laying. We replicated the Dop2R effect in an independently collected productivity dataset and showed that the effect of the Dop2R variant was mediated in part by regulatory gene expression variation. This study demonstrates the strong potential of genome-wide association analysis in this diverse panel of inbred strains and subsequent functional analyses for understanding the genetic architecture of fitness traits.

Seed stand is a natural forest population that is one of the essential seed sources for global seed supply. Individual fertility is an ability to produce progeny to next generation. Prediction of fertility variation is useful for seed quality, ecosystem management and gene conservation. Fertility variation and gene diversity in seed stands of Taurus cedar were estimated based on the difference in strobilus production between female and male parents. A total of 50 trees were randomly chosen from each stand, and female and male strobili were counted for three consecutive years. The mean of female strobili ranged from 31 to 150, and that of male ranged between 77 and 828. The variation in strobilus production was subjected to estimation of female and male fertility variation. The total fertility variation (\(\Psi\)) was estimated from the female and male fertility variation. The \(\Psi\) in a good crop year was smaller than in a poor year. The effective number of parents (Np) was calculated based on the \(\Psi\), which varied from 34.7 to 44.2. When strobilus productions were pooled across 3 years or populations, the Np increased. Equal cone harvest could mitigate the fertility variation among individuals but caused loss of seed production. Mixing seeds from different years could also decrease the fertility variation and increase the gene diversity of seeds. However, a balance between the size of Np and the number of pooling years should be carefully considered for maintaining the gene diversity in the natural stands.

The present study was carried out to evaluate fertility variation, status number and gene diversity based on strobili productions in two clonal seed orchards of Scots pine (Pinus sylvestris L.). There were large differences among clones for the female and male strobili productions in the orchards. Positive and significant (p< or =0.05) correlations were found between female and male strobili production (r = 0.76, 0.55). Female fertility variation (1.03, 1.07) was larger than male fertility variation (1.02, 1.03) in the orchards. The status numbers estimated based on the total fertility were very high (97 and 98% of census numbers). The large fertility variation could be balanced by different treatments such as mixing seed equally from clones or genetinc thinning.

Clonal variation in the number of female and male strobili was studied for three consecutive years (2002-2004) in a clonal black pine seed orchard in Turkey. The data showed large differences in female and male fertility among clones in the three years. The correlation between female and male strobilus production was negative and statistically significant in 2004, a good-flowering year. Clonal fertility and fertility variation, expressed by the sibling coefficient and coefficient of variation in strobilus production among 30 clones, were reported. Fertility varied among clones and among years, producing three-year averages of 99.3 and 801.6 for female and male strobili per ramet, respectively. Male fertility variation was higher than was female fertility variation in the three years. The status number, a measure of genetic diversity, was calculated as 26.4 (2002), 23.9 (2003), and 24.0 (2004). On average, the relative status number, estimated based on total fertility, was 86% of the census number. Sexual asymmetry calculations showed that clonal contributions would be balanced between genders. Some management activities such as adjusting ramet number to balance clone contributions and mixing of seeds from consecutive years are suggested for the black pine seed orchard.

The spatial context of reproduction is of crucial importance to plants because of their sessile habit. Since pollen and seed dispersal is often restricted, mating success is likely to depend on the quantity and quality of mates in local neighbourhoods. Here we use neighbourhood models to investigate the spatial ecology of pollination and mating in Narcissus assoanus, a sexually polymorphic plant with two mating morphs that differ in style length. By mapping individuals in eight populations from southwestern France, we investigated the influence of the density and morph identity of plants at different spatial scales on variation in female fertility. By using inferences on the expected patterns of pollen transfer based on floral morphology, we were able to predict the quantitative relations between local morph ratios and variation in fertility. Our analyses revealed differences in the spatial clustering of morphs and in their response to plant density and morph identity within local neighbourhoods. Mating success in N. assoanus was characterized by both density- and frequency-dependent processes, a condition that may be a general feature of the spatial ecology of plant mating.

The numbers of female and male flowers were assessed in a clonal seed orchard of Fraxinus rhynchophylla for four consecutive years from 2004 through 2007. The female and male flowers of the grafts from 48 clones were counted individually over the crown. Fertility variation was calculated by sibling coefficient that is related to the coefficient of variation in parental flower assessment. Estimated maternal and paternal fertilities were not constant but varied from year to year, and they were also found to be weakly correlated. The effective numbers of clones serving as male and female parents were calculated from the sibling coefficients of maternity and paternity. We applied two theoretical approaches to estimate the clonal effective population sizes based on 1) fertility variation (i.e., effective number of parents, N(c)) and 2) gender balance (effective population size, Ne e) among parental genotypes. The values of Ne (c) were higher in the years with abundant flowering and seed production, while sibling coefficients were lower. On average (pooled), the maternal, paternal and clonal values of Ne (c) were calculated to be 17.3, 21.0 and 38.1 respectively. The Ne (c) for maternal gamete gene pool was ranged from 9.8 to 16.7. The values of Ne for paternal gamete gene pool were generally higher (ranged from 14.9 to 21.9) than those for maternal. When pooled, the Ne was 47.2 and the values of Ne were higher when the gender ratio was more balanced. An option of equal seed harvest might be good to mitigate fertility variation and to improve gene diversity of seeds.

Female fertility is the basis for the output of seeds from clonal orchards and its variation is of major interest for the economics and biology of seed orchards, especially for the efficiency and diversity of seed orchard crops. Assessments of female fertility variation in 10 mature (>15 years old) seed orchards of Scots pine (Pinus sylvestris L.) were evaluated and compared. Depending on the individual orchard, fertility variation for each clone was assessed in slightly different ways, e.g. number of strobili, cones, seeds or litre of cones per ramet. Assessments in five of the orchards were made over consecutive years. The main result was that the clonal variation in mean female fertility per surviving ramet was lower than expected from the literature; the Kang–Lindgren sibling coefficient (Ψ) within individual years averaged 1.35. The variation between ramets within clones and years was of similar magnitude as that between clones. Clone by year interactions were noticeable, but were slightly lower than the variation between as well as that within clones in individual years. There was considerable variation in the variance components between years. The limited variation in female fertility indicated that it should not be a selection criterion when selecting clones for a seed orchard. Furthermore, it will not result in large differences between clones in seed set or large reductions in gene diversity in productive Scots pine seed orchards.

Few aspects of biology are linked to so many evolutionary conflicts as sperm production and fertilization. Segregation distortion and maternal inheritance of cytoplasmic genes, causing maladapted males, are common sources of variation in the competitive ability of sperm, leading males to vary in their intrinsic fertility. Here, I theoretically analyze the effect of such variation in male intrinsic fertility on ejaculate investment. The model reveals that with increasing variation in male fertility, males should overall spend less resources on their ejaculates. Furthermore, if males differing in intrinsic fertility are able to invest differently in sperm production, there are two contrasting outcomes. Typically, less fertile males should invest more. However, if female mating frequency is relatively low and differences between males relatively large, the most common male genotype should invest more. These results have important consequences both for the understanding of sperm competition strategies as well as for the evolution of female polyandry and female mating preferences.

Information about fertility variation of flowering trees in seed orchard including determining the quality of seed production and estimating the genetic diversity are still lacking. This paper evaluates fertility variation, effective population size and genetic diversity among cajuput trees in seedling seed orchard at Paliyan, Gunungkidul for optimizing seed orchard management. A total of 160 trees were observed in three flowering periods of 2011-2013. The fertility based on the number of flowers and fruits were registered for each tree at the age of 12, 13 and 14 years. Results show that there are similar patterns of fertility after three years observation. Sibling coefficients (Ψ) which show fertility variation during three flowering periods are 1.39, 1.25 and 1.43 respectively. They show deviation from random mating, because of individual imbalance for producing flowers and fruits. However, the number of fertile trees was comparatively higher at 2011. More than 15 families of effective population size were recorded each year and supported more than 75% individuals in seed orchard to contribute flowers and seeds. High value of genetic diversity was calculated based on fertility variation (0.965, 0.967 and 0.957, respectively). Fertility variation led to consequence on seed deployment, including seeds of fertile families which should be collected equally and mixed to compose equal proportion of seeds and to avoid domination of highly fertility families and genetic drift. Silvicultural treatments in seed orchard management were indispensable to promote fertility uniformity and to increase effective population size in seed orchard for obtaining maximal genetic gain.

&lt;p&gt;Information about fertility variation of flowering trees in seed orchard including determining the quality of seed production and estimating the genetic diversity are still lacking. This paper evaluates fertility variation, effective population size and genetic diversity among cajuput trees in seedling seed orchard at Paliyan, Gunungkidul for optimizing seed orchard management. A total of 160 trees were observed in three flowering periods of 2011-2013. The fertility based on the number of flowers and fruits were registered for each tree at the age of 12, 13 and 14 years. Results show that there are similar patterns of fertility after three years observation. Sibling coefficients (&Psi;) which show fertility variation during three flowering periods are 1.39, 1.25 and 1.43 respectively. They show deviation from random mating, because of individual imbalance for producing flowers and fruits. However, the number of fertile trees was comparatively higher at 2011. More than 15 families of effective population size were recorded each year and supported more than 75% individuals in seed orchard to contribute flowers and seeds. High value of genetic diversity was calculated based on fertility variation (0.965, 0.967 and 0.957, respectively). Fertility variation led to consequence on seed deployment, including seeds of fertile families which should be collected equally and mixed to compose equal proportion of seeds and to avoid domination of highly fertility families and genetic drift. Silvicultural treatments in seed orchard management were indispensable to promote fertility uniformity and to increase effective population size in seed orchard for obtaining maximal genetic gain.&lt;/p&gt;

Despite worldwide knowledge of the importance of the Galápagos archipelago, there is little comparative plot data from the forests in the dry regions. We examined patterns of woody plant (≥2.5 cm diameter at breast height (DBH)) species richness and structure using Gentry’s transect method (0.1 ha) on the three largest islands in the Galápagos. We identified the conservation status of woody plants within the dry forest region, assessed forest cover and change in the region, and compared field results to other tropical dry forests in the Pacific. Of the 22 species encountered (11 native, 11 endemic), there were no non-native species and only one threatened species. Isabela, Santa Cruz and San Cristóbal have similar overall levels of species, genera, family and liana richness per site, but significantly different tree species richness, density and tree height per transect. Geospatial databases identified 51 species (native 40%, endemic 60%) of woody plants (≥2.5 cm DBH) within the dry forest region of the Galápagos and 13 species (10 from the genus Scalesia) on the IUCN Red List. There is an estimated 551.97 km2 of dry forest in the Galápagos and there has been little change (&amp;lt;0.01%) in forest cover from 2000 to 2015. Dry forests of the Galápagos have similar levels of species richness to Hawaii and the Marquesas but contain lower densities, basal areas and tree heights than other dry forests in the Pacific. These dry forests appear to be the best preserved and protected tropical dry forest in the Pacific.

Введение. В условиях изменяющегося климата всё более актуальны оценки полного углеродного пула всех компонентов лесных экосистем, в том числе массы отмерших ветвей (МОВ) растущих деревьев. В опубликованных данных о фитомассе деревьев отношение МОВ к надземной фитомассе (ОМОВ) варьирует в диапазоне от 0,3 до 29 %, однако попытки выявить факторы, объясняющие столь широкий его диапазон, довольно редки. Цель исследования. В настоящем исследовании предпринята первая попытка разработки аллометрических моделей, предназначенных для оценки МОВ и ОМОВ растущих деревьев сосны обыкновенной естественных древостоев и культур в условиях степной и лесостепной зон. Объекты и методы. Объектом исследования послужили чистые сосняки естественного и искусственного происхождения островных боров в степной зоне Тургайского прогиба. Для сравнения использованы опубликованные данные для естественных сосняков Красноярско-Канской лесостепи и выполнена их сравнительная оценка по МОВ и ОМОВ. Всего в анализе использовано 595 модельных деревьев, взятых на 48 пробных площадях. Результаты. Анализ парных связей МОВ с дендрометрическими характеристиками деревьев показал, что диаметр ствола объясняет от 87 до 92 % и высота дерева от 81 до 88 % изменчивости МОВ. При увеличении диаметра ствола с 6 до 26 см ОМОВ в Тургайской степи в культурах повышается с 6 до 13 %, а в естественных сосняках остаётся стабильной на уровне 4 %. Сравнительный анализ МОВ деревьев в культурах и естественных сосняках, выполненный по двухфакторной модели зависимости от диаметра ствола и высоты дерева, показал, что МОВ в культурах по сравнению с естественными древостоями выше в 1,8 раза. Сравнительный анализ МОВ деревьев в естественных сосняках Тургайской степи и Красноярско-Канской лесостепи показал, что их различие небольшое, и в среднем при увеличении диаметра ствола от 6 до 26 см МОВ изменяется с 0,3 до 9 кг, а ОМОВ остаётся стабильной на уровне 4 %. При увеличении возраста при неизменном диаметре ствола ОМОВ в естественных сосняках двух регионов снижается с 10–19 до 2–4 %. Вывод. При расчётах углеродных пулов надземной фитомассы необходимо вносить поправки в оценку пула в культурах сосны степной зоны в виде 6–13 %-ного и в естественных сосняках cтепной и лесостепной зон в виде 4 %-ного повышения за счёт МОВ. Introduction. In a changing climate, estimates of the total carbon pool of all components of forest ecosystems, including the mass of dead branches (DBM) of standing trees, are increasingly relevant. According to published data on the tree phytomass, the ratio of DBM to the aboveground phytomass, or relative DBM (RDBM), ranges from 0.3 to 29 %. However, attempts to identify the factors explaining such a wide range have been quite rare. The aim of the study. In this research, the first attempt was made to develop allometric models for estimating DBM and RDBM of Pinus sylvestris L. trees growing in the natural forest stands and plantations of the steppe and forest-steppe zones. Objects and methods. The object of the study was pure island pine forests of natural and artificial origin located in the steppe area of the Turgay Depression. For comparative purposes, published data on natural Pinus sylvestris L. forests of the Krasnoyarsk and Kansk forest steppe were utilized; their comparative evaluation in regard to DBM and RDBM was carried out. In total, 595 model trees taken from 48 sample plots were used for the analysis. Results. The analysis of paired associations of DBM with dendrometric tree characteristics showed that the trunk diameter at breast height (DBH) accounts for 87-92 % of DBM variability, and the tree height accounts for 81- 88 % of it. With an increase in DBH from 6 to 26 cm, RDBM in the Turgay steppe plantations rises from 6 to 13 %, while in natural pines forests it remains stable at 4 %. A comparative analysis of DBM of trees in plantations and natural forest stands, which was performed using a two-factor model depending on DBH and the tree height, showed that DBM in plantations was 1.8 times higher than that in natural stands. A comparative analysis of DBM of trees in the natural pine forests of the Turgay steppe and the Krasnoyarsk and Kansk forest-steppe revealed little difference; on average, with an increase in DBH from 6 to 26 cm, DBM changes from 0.3 to 9 kg, while RDBM remains stable at 4 %. With increasing age and constant DBH, RDBM in the natural pine forests of the two regions decreases from 10-19 % to 2-4 %. Conclusion. When calculating the carbon pools of the aboveground phytomass, it is necessary to make a correction to the pool estimate as a 6-13% increase for the steppe zone pine plantations, and as an increase of 4 % for the natural pine forests of the steppe and forest-steppe zones.