Variation In Reproductive Characteristics Research Articles

Understanding Patterns of Life History Trait Covariation in an Untapped Resource, the Lab Mouse.

AbstractThrough artificial selection and inbreeding, strains of laboratory mice have been developed that vary in the expression of a single or suite of desired traits valuable to biomedical research. In addition to the selected trait(s), these strains also display variation in pelage color, body size, physiology, and life history. This article exploits the broad phenotypic variation across lab mouse strains to evaluate the relationships between life history and metabolism. Life history variation tends to exist along a fast-slow continuum. There has been considerable interest in understanding the ecological and evolutionary factors underlying life history variation and the physiological and metabolic processes that support them. Yet it remains unclear how these key traits scale across hierarchical levels, as ambiguous empirical support has been garnered at the intraspecific level. Within-species investigations have been thwarted by methodological constraints and environmental factors that obscure the genetic architecture underlying the hypothesized functional integration of life history and metabolic traits. In this analysis, we used the publicly available Mouse Phenome Database by the Jackson Laboratory to investigate the relationships among life history traits (e.g., body size, reproduction, and life span) and metabolic traits (e.g., daily energy expenditure and insulin-like growth factor 1 concentration). Our findings revealed significant variation in reproductive characteristics across strains of mice as well as relationships among life history and metabolic traits. We found evidence of variation along the fast-slow life history continuum, though the direction of some relationships among these traits deviated from interspecific predictions laid out in previous literature. Furthermore, our results suggest that the strength of these relationships are strongest earlier in life.

Variations in Reproductive Characteristics among Oreochromis niloticus Populations of Three Ethiopian Rift Valley Lakes

Variations in Reproductive Characteristics among Oreochromis niloticus Populations of Three Ethiopian Rift Valley Lakes

The Reproductive Strategy of Hermit Crabs in Temperate Waters

This review examines the main characteristics of the reproductive strategy in hermit crabs: the sex ratio, the age (size) of onset of maturity, fecundity, and duration of the incubation period, as well as their dependence on the availability and quality of accessible gastropod shells. The latitudinal variation in reproductive characteristics and the peculiarities of reproduction of coastal hermit crabs in temperate waters are discussed.

Some reproductive biology parameters of mosquitofish Gambusia holbrooki Girard, 1859 (Poeciliidae) in some waterbodies of southeastern Caspian basin, Iran

Eastern mosquitofish, Gambusia holbrooki , is an invasive exotic fish for Iranian inland water. This study conducted to evaluate some reproductive traits of this species in six waterbodies from southeastern Caspian basin. A total of 8500 individuals were sampled from the AlmaGol Wetland, Alakooli Dam Lake, Gomishan Lagoon, Voshmgir Dam Lake, Golestan Dam Lake, and estuary of Gorgan River during February to September 2014. The maximum age in all areas was 1 + for males and 2 + for females. The highest mean GSI value was 2.6 for males in April-May and 29.6 for females in May. Egg diameter ranged from 0.5 to 2.5 mm with a mean value of 1.43 mm. Absolute fecundity varied between 2 to 212 eggs. Both ova diameter and absolute fecundity were positively correlated with females' size, while relative fecundity had no significant correlation with females' size (length and weight). The results showed a significant variations in reproductive characteristics among the populations inhabiting different habitats. This finding is important with respect to life history of the species and ecological view as well.

Acetolactate Synthase–Inhibitor Resistance in Yellow Nutsedge (Cyperus esculentus): II—Physiognomy and Photoperiodic Response

Yellow nutsedge is one of the most problematic weedy sedges in rice–soybean systems of the Mississippi Delta region. An acetolactate synthase (ALS)-inhibiting, herbicide-resistant (Res) yellow nutsedge biotype was recently documented in eastern Arkansas, which showed intermediary growth habit between yellow nutsedge and purple nutsedge and also exhibited differential photoperiodic sensitivity to flowering. The objectives of this study were to: (a) determine variation in reproductive characteristics of theResbiotype and three susceptible (Sus) yellow nutsedge biotypes, (b) understand the influence of photoperiod on growth and reproduction, (c) understand the potential role of seeds in population establishment, and (d) elucidate the phylogenetic relationships between theResyellow nutsedge biotype and purple nutsedge. Tuber production per plant and tuber weight of theResbiotype were less than that of theSusbiotypes. Differences in quantitative traits, such as shoot and tuber production existed between theResandSusbiotypes for photoperiods ranging from 12 to 16 h. Generally, photoperiods greater than 12 h increased shoot development in all yellow nutsedge biotypes, with differential responses among the biotypes. Number of tubers reached the maximum for theResbiotype at a 14-h photoperiod. Over a 90-d period, inflorescence formation was only observed in theResbiotype with maximum flowering and seed production in the 14-h photoperiod. Subsequent tests revealed up to 18% seed germination, suggesting that seed could also play a role (in addition to tubers) in the persistence and spread of theResyellow nutsedge. Phylogenetic analysis based on ribosomal DNA internal transcribed spacer (ITS) regions and mitochondrialnad4gene intergenic spacer sequences indicated that theResbiotype was more closely associated withSusyellow nutsedge biotypes. Nevertheless, 100% similarity for thenad4gene sequences between theResyellow nutsedge biotype and a reference purple nutsedge suggests that theResbiotype is likely a result of hybridization between yellow and purple nutsedges, which perhaps explains the intermediary growth characteristics observed in theResbiotype.

Marked variations in reproductive characteristics of snapper (Chrysophrys auratus, Sparidae) and their relationship with temperature over a wide latitudinal range

Abstract The timing and duration of spawning and maturation schedules of Chrysophrys auratus were determined for populations in one subtropical (∼25°S on the upper west coast) and two temperate regions (∼32°S on the lower west and ∼35°S on the south coasts) over >2000 km of coastline along the west coast of Australia. This study thus encompassed the wide latitudinal range of this recreationally and commercially important sparid in this region. The results were used, in conjunction with previously published data, to explore traditional paradigms regarding the relationships between the reproductive characteristics and variations in water temperature. Spawning at each latitude occurred mainly at 19–21°C, but following a decline in temperature in the subtropical region and after a rise in temperature in the two temperate regions. Spawning on the upper west coast thus occurred between mid-autumn and early spring (∼7 months) as opposed to late winter to early summer on the lower west coast (∼6 months). Spawning on the south coast was mainly restricted to mid-spring to early summer (∼2–3 months) in 2003 and 2004 and did not occur in 2005 when temperatures in this period were the coldest on record. Thus, marked interannual differences in the prevalence of mature fish on the south coast probably reflect the “marginality” of the population. The length (L50) and age (A50) at which C. auratus matured increased markedly from 25 to 32°S. Studies such as this allow for latitudinal variations in reproductive characteristics to be incorporated into population models to optimize fisheries sustainable yield, and contribute towards appropriate spatial scales for sustainable management strategies (e.g. minimum legal lengths consistent with latitudinal variation in length-based maturity schedules). The narrow temperature range over which this species spawns accounts for its current latitudinal distribution and enables predictions of how this distribution might alter with climate change. This study provides relevant information for management and climate change implications for similar subtropical and temperate marine teleosts.

Intra-population trends in the maturation and reproduction of a temperate marine herbivore Girella elevata across latitudinal clines.

Latitudinal variation in the reproductive characteristics of a temperate marine herbivore, rock blackfish Girella elevata, was examined from three regions of the south-eastern Australian coast. Biological sampling covered 780 km of coastline, including the majority of the species distribution. The sampling range incorporated three distinct oceanographic regions of the East Australian Current, a poleward-flowing western boundary current of the Southern Pacific Gyre and climate-change hotspot. Girella elevata are a highly fecund, group synchronous (multiple batch)-spawner. Mean fork length (LF ) and age at maturity were greater for females than males within all regions, with both male and female G. elevata of the southern region maturing at a greater size and age than those from the central region. Estimates of batch fecundity (FB ) were greatest in the northern and southern regions, relative to the central region where growth rates were greatest. Significant positive relationships were observed between FB and LF , and FB and total fish mass. Gonado-somatic indices indicated latitudinal synchrony in spawning seasonality between G. elevata at higher latitudes, spawning in the late austral spring and summer. A late or prolonged spawning period is evident for G. elevata from the northern region. Juvenile recruitment to intertidal rock pools within the central and southern regions was synchronous with the spawning season, however, no juveniles were found within the northern region. The implications of latitudinal variation in reproductive characteristics are discussed in the context of climate and oceanographic conditions of south-east Australia.

Family Planning: Does Variation in Reproductive Strategies Affect Vulnerability to Extinction in the Greater Spear-Nosed BatPhyllostomus Hastatus?

Different reproductive strategies among populations might affect population growth rates, and a population's vulnerability to threats. Population viability analysis may help guide population management and the identification of populations more prone to decline, allowing a preventive approach to avoid population declines and extinctions. The objective of the present study was to evaluate if differences in reproductive strategy translate into differential intrinsic vulnerability among different populations of Phyllostomus hastatus. We used the software VORTEX to model the dynamics and viability of P. hastatus populations under different reproductive scenarios. We modeled a total of 12 scenarios evaluating variations in reproductive characteristics of the species (monoestry vs polyestry, harem size, and infant mortality rate). Phyllostomus hastatus populations were viable under most scenarios, except with scenarios incorporating monoestry and high pup mortality. Our results demonstrate that both reproductive strategies (monoestry and polyestry) found in P. hastatus result in viable and stable populations under natural conditions. However, polyestrous populations have higher growth rates, making them more resilient to natural and/or anthropogenic disturbances. A significant portion of the more resilient populations in South America overlap the Amazon Forest, a continuous and preserved habitat under low human pressure, which bodes well for the long-term persistence of these populations. On the other hand, the populations of the species that evolved the monoestrous reproductive strategy are located in Mesoamerica, a Biodiversity Hotspot that is under severe human impacts, particularly from habitat loss. Conservation biologists and managers must take into account intra-specific demographic differences of species when planning for their long-term persistence.

Reproductive performance in female strains of Nile tilapia, Oreochromis niloticus

The Nile tilapia is among the most cultivated tropical fish in the world, yet little is known about the variations in reproductive characteristics among different strains. There is an interest in evaluating the reproductive performance of females of three tilapia strains. All strains were represented in equal proportion (n = 225), being named as Supreme (SUP), Premium Aquabel (PA), and Chitralada (CHI). These fish were cultivated for 7 weeks in the Aquabel Pisciculture Station (Brazil), from January to March 2011. The PA was the largest strain, with the highest values in all the morphometric parameters we analyzed (weight, total length, standard length and body depth). Among the evaluated reproductive parameters, the PA strain differed significantly from the other two in number and weight of eggs/female, volume of eggs/spawn and number of eggs/kg of fish. The percentage of non-spawning females in the SUP and CHI strains differed significantly from one another, while results for PA showed intermediate values and no significance compared to the other strains (P > 0.05). Among the reproductive parameters analyzed, the percentage of spawned females/week, more than one spawns during 7 weeks, and hatching rate showed no significant differences between strains (P > 0.05). There was a significant correlation (r = 0.69) between water temperature and percentage of spawned females/week. When evaluating the interval between two consecutive spawns, we observed that periods of 21 days were the most frequent in all strains. In conclusion, the strain that showed the best results in all morphometric and in most reproductive parameters we evaluated was the PA.

Assessing the effectiveness of size limits and escape gaps as management tools in a commercial rock lobster ( Jasus edwardsii) fishery

Minimum legal sizes (MLSs) and escape gaps are two commonly used management tools within commercial lobster fisheries. This study examined their effectiveness within the spatially expansive (∼207,000 km 2) Northern Zone rock lobster ( Jasus edwardsii) fishery of South Australia. Firstly, spatially explicit estimates of size of maturity (SOM) and relative reproductive potential were estimated to examine if the current minimum legal size of 105 mm carapace length (CL) was appropriate. Size of maturity ranged from 105 to 118 mm CL with 90% of reproductive potential coming from size classes above 105 mm CL. SOM generally tended to increase from east to west and indicated that while the current MLS of 105 mm CL may be appropriate for Marine Fishing Areas (MFAs) in the eastern part of the fishery, a higher MLS (>110 mm CL) should be considered for MFAs in the western region of the zone. As size of maturity is age, rather than size dependent, these results may reflect differences in growth rates and highlight the importance of considering spatial variation in reproductive characteristics when applying size limits to lobster resources. Escape gap effectiveness was examined by estimating catch rates of undersized lobsters and commonly caught bycatch species, before and after mandatory introduction in 2003. After 2003, catch rates of undersized lobsters decreased by >60% while blue-throat wrasse ( Notolabrus tetricus) and leatherjacket species ( Meuschenia hippocrepis and Meuschenia australis) decreased by >50%. The findings have implications for the Southern Zone of South Australia where fishing effort is substantially higher but where escape gaps are not mandatory.

Demography, reproduction, and dormancy along altitudinal gradients in three intermountain Allium species with contrasting abundance and distribution

Little is known about the variation in demographics, flower number, fruit set, and summer dormancy in Allium species native to the Intermountain West region of the United States. The purpose of this study was to investigate demographic patterns, summer dormancy traits, and variation in reproductive characteristics among habitats. Three populations of each of three species, Allium acuminatum, A. brandegei, and A. passeyi, were studied along an altitudinal gradient in northern Utah, USA, from 2004 to 2006. Demographic data were collected from individuals in permanent plots established in each population. Individual flowering plants were periodically monitored and used to calculate reproductive characteristics. Leaf area measurements throughout the 2005 growing season and soil temperature sensors were used to assess the relationship between habitat and dormancy characteristics. Populations of the widely distributed species, A. acuminatum and A. brandegei, were dominated by individuals in seedling and flowering stages while the restricted A. passeyi had populations containing a majority of individuals in the post-seedling, but non-flowering stage-class. There was a strong directional trend in A. acuminatum reproductive traits, with flower number and fruit set decreasing with increasing elevation. The mid-elevation A. brandegei populations were reproductively more successful than the high and low-elevation populations. The high-elevation A. passeyi population had more flowers per plant and higher fruit set in comparison to the lower elevation populations. The onset of summer dormancy as indicated by the timing of leaf senescence, was associated with high soil temperatures specific to each species. In general, the timing of leaf senescence was later in higher elevation populations in all species. A smaller proportion of non-flowering individuals in A. acuminatum and A. brandegei may indicate a high seedling mortality rate or a shorter juvenile phase in comparison to A. passeyi. The A. passeyi populations exhibit demographic characteristics of rare taxa; low seed production and low seedling recruitment. The high number of non-flowering plants in A. passeyi likely includes many reproductively mature individuals which are influenced by the unique habitat and environment of this species. Temperature is likely the key environmental cue inducing summer dormancy in all three species.

Temporal variation in reproductive characteristics of an introduced and abundant island population of koalas

Reproductive characteristics of a wildlife population are typically sensitive to changes in environmental conditions and intrinsic factors. Knowledge of these relationships is critical for understanding population dynamics and effective long-term management of a population. We examined temporal variation in reproductive parameters of an abundant, genetically compromised, and high-density population of koalas (Phascolarctos cinereus) on Kangaroo Island, South Australia, over 3 breeding seasons spanning 9 years: November–May of 1997–1998, 2005–2006, and 2006–2007. Timing of the breeding season was consistent between years, but fecundity, sex ratio of young, and the percentage of independent females (those not accompanying a lactating female) , 6 kg varied. Fecundity was lower than in other island populations, suggesting that the quality and distribution of food resources or inbreeding may be impacting the Kangaroo Island population. We did not test for Chlamydophila (synonym 5 Chlamydia), and clinical signs of this disease were not reported for any of the koalas in this study. However, historical evidence of Chlamydophila-infected koalas on Kangaroo Island exists, and the potential impact of this disease on fecundity warrants further investigation. DOI: 10.1644/09-MAMM-A-384.1.

Riding across the selection landscape: fitness consequences of annual variation in reproductive characteristics.

Evolutionary models estimating phenotypic selection in character size usually assume that the character is invariant across reproductive bouts. We show that variation in the size of reproductive traits may be large over multiple events and can influence fitness in organisms where these traits are produced anew each season. With data from populations of two orchid species, Caladenia valida and Tolumnia variegata, we used Bayesian statistics to investigate the effect on the distribution in fitness of individuals when the fitness landscape is not flat and when characters vary across reproductive bouts. Inconsistency in character size across reproductive periods within an individual increases the uncertainty of mean fitness and, consequently, the uncertainty in individual fitness. The trajectory of selection is likely to be muddled as a consequence of variation in morphology of individuals across reproductive bouts. The frequency and amplitude of such changes will certainly affect the dynamics between selection and genetic drift.

Microgeographic Variation in Reproductive Characteristics among Western Rattlesnake (Crotalus oreganus) Populations

Studies on geographic variation in reproductive characteristics can contribute to an understanding of the effects of environmental factors on animal population structure and dynamics. Using a ten-year mark–recapture data set (1994–2003), we studied microgeographic variation in reproductive characteristics (body condition, growth, age to maturity, pregnancy interval, fecundity, and size of offspring) among three Western Rattlesnake (Crotalus oreganus) populations within 40 km of each other. Significant differences existed among snakes from the different den sites in length, body condition, growth rate, fecundity, and size and body condition of offspring. Furthermore, there was a consistent pattern in the variation among populations. Individuals from the population in the most disturbed area, were shorter, had lower body condition, grew slower, had lower fecundity, and had shorter and lower body condition offspring compared to other populations. The results from this study have important applied implications for understanding fine scale variation in reproductive characteristics. This study suggests that some rattlesnake populations have reproductive characteristics that may make them more susceptible to future disturbances.

Spatial variations in reproductive characteristics of the small copepod Oithona similis in the Barents Sea

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 386:133-146 (2009) - DOI: https://doi.org/10.3354/meps08085 Spatial variations in reproductive characteristics of the small copepod Oithona similis in the Barents Sea Vladimir G. Dvoretsky*, Alexander G. Dvoretsky Murmansk Marine Biological Institute, Kola Scientific Centre, Russian Academy of Sciences, 17 Str. Vladimirskaya, Murmansk 183010, Russia *Email: vdvoretskiy@mmbi.info ABSTRACT: In the Barents Sea during late summer 2006 and 2007 we investigated spatial variations in the biomass, abundance, reproductive characteristics and production of Oithona similis (copepodite stages IV to V and adults), the most abundant small copepod. The species contributed 0.1 to 15.3% of the total mesozooplankton biomass. Adults were the most abundant stage in 2006 while younger copepodites prevailed in 2007. Prosome length of all stages was negatively and significantly correlated with water temperature. The mean (±SE) relative abundance of ovigerous females and mean (±SE) clutch size were 31 ± 1 and 38 ± 2%; and 22 ± 0 and 21 ± 0 eggs per sac in 2006 and 2007, respectively. Egg diameter (D) varied from 45 (in the south) to 70 µm (in the north). Egg production rates (EPR) varied from 0.2 to 1.8 eggs female–1 d–1 in both periods. Specific egg production rates (SEPR) were 0.005 to 0.029 and 0.008 to 0.04 d–1 in 2006 and 2007, respectively. The total secondary production of O. similis varied between stations and between years from 12 to 2714 µgC m–2 d–1. Copepodites V contributed the main part of the total secondary production (47 ± 2 in 2006 and 52 ± 3% in 2007). Multiple regression analysis showed that temperature and salinity explained 50 to 92 and 63 to 93% of the total variations in the log10-transformed D, EPR and SEPR in 2006 and 2007, respectively. Although 4 regions were separated on the basis of water temperature and salinity, 3 populations of O. similis were delineated by cluster analysis based on the species mean reproductive characteristics. This corresponds with our data based on the analysis of morphological parameters of O. similis in the Barents Sea (Dvoretsky & Dvoretsky 2009; Mar Ecol Prog Ser 385:165–178). KEY WORDS: Oithona similis · Copepod · Barents Sea · Biomass · Secondary production Full text in pdf format PreviousNextCite this article as: Dvoretsky VG, Dvoretsky AG (2009) Spatial variations in reproductive characteristics of the small copepod Oithona similis in the Barents Sea. Mar Ecol Prog Ser 386:133-146. https://doi.org/10.3354/meps08085Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 386. Online publication date: July 02, 2009 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2009 Inter-Research.

Integrating Reproductive Biology into Scientific Advice for Fisheries Management

An understanding of the reproductive biology of a species is a central aspect of providing sound scientific advice for fisheries management. Reproductive biology plays a large part in determining productivity and therefore a population’s resiliency to exploitation by fisheries or to perturbation caused by other human activities. This paper provides an overview of variation in reproductive characteristics in commercial fish species and examines the impact on perceived productivity. It is clear that accounting for variation in reproductive biology can have a major impact on advice for fisheries management. Further work is required on the methods used to estimate reproductive characteristics such as maturation, sex ratio, and fecundity, and research to better understand the tradeoffs leading to variation in these reproductive traits. It will also be necessary to demonstrate that incorporating more complex estimates of reproductive potential results in better scientific advice for fisheries manage ment.

Natural post-fire dynamics and serotiny in 10-year-old Pinus halepensis Mill. stands along a geographic gradient

In 1994, six large fires occurred along a climate gradient in Eastern Spain. Ten-year-old trees were selected in the plots established for each location affected by fire. Each selected tree was measured for height and trunk diameter, the number of female strobili and cones, and grouped into four types. A geographical gradient was determined to study growth by latitude and variations in reproductive characteristics. Height and diameter values decreased southwards with the exception of the lowest-density tree location, where trunk diameters were similar to those in northern locations. Strobilus and cone production were higher in lower tree density locations owing to intraspecific competition and higher availability of water, nutrients and light. Serotiny levels were highest in southern locations, although lower percentages were found in the southern locations with low tree density. The number of reproductive trees was higher with lower tree density. The reproductive phase was reached in the lowest tree density site (also low site quality) and nearly reached in the most northern locations (high tree density as well as high site quality). Results showed a geographical gradient based on growth and reproduction dynamics, where serotiny levels are higher in southern locations. Density was shown to be a significant factor influencing overall pine stand development.

Density effects on length at maturity of walleye pollock Theragra chalcogramma off the Pacific coast of northern Japan in the 1990s

To determine how stock abundance fluctuations of walleye pollock Theragra chalcogramma are related to variations in reproductive characteristics, the length at 50% maturity of the fish sampled off the Pacific coast of northern Japan from 1990 to 1999 was examined. In both sexes, the fish density increased, and the body length of age-3-5 fish decreased, but the condition factor and the age at 50% maturity showed no clear trend during this period. Male length at 50% maturity decreased, while value for females showed no clear trend. In both sexes, significant negative correlations were found between density index (combined age-3-5) and each body length at age-3-5. Significant positive correlations were seen between each body length at age-3-5 and length at 50% maturity in males. Positive correlation between body length at age-5 and length at 50% maturity was significant in females from 1990 to 1999, except for the samples in 1998. We suggest that the fish density might affect the length at maturity in males and possibly also in females.

Variation in reproductive characteristics of Eupatorium adenophorum populations in different habitats

SummaryThe invasive plant, Eupatorium adenophorum, produces large numbers of small seeds with a high germination rate. However, this investigation showed that E. adenophorum populations in an evergreen broad‐leaved forest had a high proportion of seedlings when compared with clonal plants. Whereas an opposite pattern was found in a deciduous broad‐leaved forest and in a roadside site. A seed addition experiment where E. adenophorum seeds were added to each of the three habitats did not increase the number of E. adenophorum seedlings at any of the three field sites. Field and greenhouse experiments demonstrated that a soil litter layer significantly reduced the number of E. adenophorum seedlings during the early seedling emergence period. However, at later periods, the litter cover did not affect survival and growth of individuals. The emergence of E. adenophorum seedlings was significantly increased in field experiments when there was no litter, and parental plants were removed. Finally, the growth of seedlings was significantly reduced when planted with their parental plants in a root box experiment. In the low‐resource environment of the evergreen broad‐leaved forest, E. adenophorum reproduced primarily by its abundant seed production. In the more open deciduous broad‐leaved forest and roadside site, the populations reproduce primarily by vegetative clones that can grow quickly, are better competitors and could take advantage of the high‐resource environment.

Variation in Reproductive Characteristics and Seed Production in the USDA Garlic Germplasm Collection

Diverse garlic germplasm has proven to be essential for production of true seed. Yet, fertile accessions in garlic germplasm collections have not been characterized for breeders and researchers, and information on morphological characteristics associated with seed producing plants is very limited. The objective of this study was to evaluate reproductive characteristics and true seed production capacity in the USDA garlic germplasm collection. Most stable traits, such as flower stem appearance, opening ability of spathe, level of difficulty to remove bulbils, tepal color, umbel shape, and the number of flowers per umbel, were similar across populations evaluated. Other characteristics including position of stigma, tepal closure, pollen viability, time of flowering, scape senescence rate, and number of seeds produced by individual plants varied within accession evaluated. Of 47 accessions, 19 produced true seeds (from 48.5 to 1.5 seeds per plant) in the Central Valley of California. Seed production in the germplasm evaluated is adequate to initiate garlic breeding projects.