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Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Information on levels of genetic variation is a prerequisite for successful natural resource management and genetic improvement programs. In this study we aimed to identify genetically distinct stocks of North African catfish, Clarias gariepinus (Burchell, 1822) in Thailand which could be used as germplasm sources for a selective breeding program. Four hatchery stocks (n = 50 fish/population) were sampled, three from northeastern provinces (Sakon Nakhon, SN; Nong Khai, NK; and Nakhon Ratchasima, NR), and one from central Thailand (Nakhon Nayok, NY). Six microsatellite loci were scored using primers developed for this species. The results revealed significant genetic differentiation among stocks (FST = 0.096; CI = 0.045-0.166) with all but one pair of stocks (NK vs SN) being significantly different, as shown by pair-wise FST. Three stocks showed homozygote excess. Further analyses showed no recent bottlenecks, but some evidence of genotype disequilibrium. Allele diversity was low (A ranged from 6.00-7.00; Ae ranged from 3.43-4.59) while heterozygosity was moderate (Ho ranged from 0.52-0.72; He ranged from 0.67-0.77). The effective population sizes (Ne) based on linkage disequilibrium method were between 22.2 and 133 individuals. The neighbor-joining (NJ) tree was robust and revealed the closest genetic relationship between SN and NK, which were clearly separated from NR and NY. Two groups of stocks (northeastern, NK+NR+SN vs NY) showed highest variation among groups (13%) as revealed by AMOVA. The results apparently revealed genetically distinct stocks of North African catfish in Thailand which are useful for establishing a base population for a genetic improvement program. [ABSTRACT FROM AUTHOR]

Catla catla is the second most important Indian major carp due to high growth rate and acceptance to consumers for food value. It is widely cultured in the Indian subcontinent as monoculture or polyculture. In the present study, genetic diversity among hatchery stocks (total 218 samples of catla) collected from different geographical regions of India was examined using mtDNA fragment sequence of Cyt b (306 bp) and D loop (710 bp). High numbers (57) of population specific haplotypes were observed in the present study. The results revealed significant genetic heterogeneity for the sequence data (FST = 0.27546, p < .05). Analysis of molecular variance revealed significant genetic differentiation among different catla populations. The information generated in present study could be useful to develop broad genetic base populations of catla. [ABSTRACT FROM AUTHOR]

Copyright of Lithuanian Journal of Statistics / Lietuvos Statistikos Darbai is the property of Lithuanian Statistical Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The phenotypic and microsatellite marker information of nine strains of catla (Catla catla) for growth trait was used to infer relationship within and between strains. This information helped in optimizing the proportion of individuals to be used from each strain while creating a base population for selective breeding. For this purpose, nine strains were collected from different sources and places of India namely West Bengal, Bihar, Odisha, Andhra Pradesh and Uttar Pradesh. Two riverine sources i.e. Ganga and Subarnarekha were also represented among the nine strains collected for base population. They were brought to Indian Council of Agricultural Research-Central Institute of Freshwater Aquaculture (ICAR-CIFA) at fry stage and reared separately till fingerlings. After passive integrated transponder tagging fingerlings were stocked in three communal ponds for one year culture. Live body weights were then measured and least square means were obtained after pond effect correction. A wide range of variation was observed among and between strains. Microsatellite markers were used to estimate genetic differences of different strains of catla using pair wise FST estimates. Overall multi locus FST, including all loci was estimated to be 0.4137 (P<0.05), indicating genetic heterogeneity among them. Analysis of molecular variance revealed that, 58.63% of variation was due to within individual variation, 3.45% of variation was due to among individuals within strain and 37.92% was due to among strain variations. Both phenotypic as well as microsatellite data will be used to form a base population of catla with individuals from the stock having broad genetic variation for selective breeding programme. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Studies in Population is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

1. Quantifying and predicting microevolutionary responses to environmental change requires unbiased estimation of quantitative genetic parameters in wild populations. 'Animal models', which utilize pedigree data to separate genetic and environmental effects on phenotypes, provide powerful means to estimate key parameters and have revolutionized quantitative genetic analyses of wild populations. 2. However, pedigrees collected in wild populations commonly contain many individuals with unknown parents. When unknown parents are non-randomly associated with genetic values for focal traits, animal model parameter estimates can be severely biased. Yet, such bias has not previously been highlighted and statistical methods designed to minimize such biases have not been implemented in evolutionary ecology. 3. We first illustrate how the occurrence of non-random unknown parents in population pedigrees can substantially bias animal model predictions of breeding values and estimates of additive genetic variance, and create spurious temporal trends in predicted breeding values in the absence of local selection. We then introduce 'genetic group' methods, which were developed in agricultural science, and explain how these methods can minimize bias in quantitative genetic parameter estimates stemming from genetic heterogeneity among individuals with unknown parents. 4. We summarize the conceptual foundations of genetic group animal models and provide extensive, step-by-step tutorials that demonstrate how to fit such models in a variety of software programs. Furthermore, we provide new functions in R that extend current software capabilities and provide a standardized approach across software programs to implement genetic group methods. 5. Beyond simply alleviating bias, genetic group animal models can directly estimate new parameters pertaining to key biological processes. We discuss one such example, where genetic group methods potentially allow the microevolutionary consequences of local selection to be distinguished from effects of immigration and resulting gene flow. 6. We highlight some remaining limitations of genetic group models and discuss opportunities for further development and application in evolutionary ecology. We suggest that genetic group methods should no longer be overlooked by evolutionary ecologists, but should become standard components of the toolkit for animal model analyses of wild population data sets. [ABSTRACT FROM AUTHOR]

A base population of the bay scallop, Argopecten irradians irradians Lamarck, was produced by crossing two cultured bay scallop populations. After 1 year of rearing, the top 10% truncation selection of the top 10% ( i=1.755) was carried out in the base population of about 1300 adults. A control parental group with a an identical number to the select parental group was randomly selected from the entire population before isolation of the select parental group. The result showed that, at the larval stage, the growth rate of larvae in the selected line was significantly higher than that of the control ( P<0.05), and that the genetic gain was 6.78%. Owing to the lower density of control at the spat stage, the mean shell length of the control line was larger than that of the select line at day 100. When the same density was adjusted between two lines in the grow-out stage (from day 100 to 160), the daily growth rate of the selected line was significantly higher than that of the control line ( P<0.05). Survival of the select line was significantly larger than that of the control line in the grow-out stage. In conclusion, the results obtained from this experiment indicate that selective breeding from a base population with a high genetic diversity established by mass spawning between different populations appears to be a promising method of genetic improvement in bay scallop, A. irradians irradians Lamarck. [ABSTRACT FROM AUTHOR]

Simple Summary: The production of domestic geese in Egypt depends mainly on small-sized flocks reared by smallholder farmers in villages, and until now, there have been no intensive or commercial goose farms in Egypt. The objective of this study was to characterize three domestic Egyptian goose populations (Kafr El-Sheikh, Fayoum and Luxor) phenotypically and genetically in order to identify the populations with the highest diversity to establish a large base population with a broad variation. Phenotypic characterization of 402 domestic mature geese included morphological measurements such as head length, culmen length, bill width, tarsus length, sternum length and chest circumference. Genetic characterization of 173 individuals was performed based on mutations in the mitochondrial D-loop region and the genotyping of 12 microsatellite markers. The results showed low population differentiation based on morphological measurements and low genetic differentiation based on the two used genetic markers. The low differentiation between the three investigated goose populations implies their suitability for aggregation and formation of a large founder population with high genetic variation. The information from this study could be useful for further investigation in order to develop a convenient conservation program for this important species. The objectives of this study were to achieve phenotypic characterization of three domestic Egyptian goose populations collected from three different geographical zones (Kafr El-Sheikh, Fayoum and Luxor) and to perform genetic characterization of these three populations based on mtDNA D-loop and 12 microsatellite markers. The body measurements of 402 domestic mature geese belonging to these three governorates showed that the lengths of the head, culmen and tarsus and the live body weight varied significantly among the three studied Egyptian goose populations. After alignment of a 710-base-pair segment of the goose mtDNA control region, there was a single haplotype in the three Egyptian goose populations, indicating the same maternal origins. The genotyping of the 12 microsatellite markers showed low diversity indices, including average observed (NA) and effective (NE) number of alleles and observed (HO) and expected heterozygosity (HE) (3.333, 1.760, 0.277 and 0.352, respectively), and a high inbreeding coefficient (FIS = 0.203) across the three Egyptian goose populations. The high inbreeding and low genetic and morphological differentiation of Egyptian geese could be corrected by establishing a large base population through capturing small populations with the highest genetic variation. The findings of the current study can therefore serve as an initial guide to design further investigations for developing conservation programs of Egyptian geese genetic resources. [ABSTRACT FROM AUTHOR]