Genetic Distance Coefficients Research Articles

Genetska analiza gradskih golubova (Columba livia) kroz markere povezane s bojom perja u općini Montería, Córdoba, Kolumbija

The species known as the domestic pigeon, scientifically Columba livia, has managed to establish itself successfully in urban environments of numerous cities around the world. This expansion has become so significant that it has triggered concerns related to its tendency to nest in human-built structures. This nesting behaviour has contributed to the deterioration of these buildings. The distinctive presence of these birds in neighbourhoods and plazas has generated a growing interest in better understanding the genetic patterns that encode their varied coloration and plumage designs. The aim of this study was to investigate the genetic variability of the population of domestic pigeons (Columba livia) in Montería, Colombia, using phenotypic markers of plumage. Random sampling was conducted between March and April 2023 on 21 flocks of pigeons within the municipality of Montería. Through urban excursions, direct observation, and photographic records, 1570 individuals were phenotypically classified. Autosomal markers encoding coloration and plumage design were studied: Checker (C), Grizzle (G), Spread (S), and Ash-Red (B). The genetic profiles of subpopulations of domestic pigeons were established using the following genetic population indices: expected heterozygosity (He), total genetic diversity (HT), diversity within populations (HS), diversity between populations (DST), coefficient of genetic diversity (GST), gene flow (Nm), and genetic distance between populations. It was found that the most common allele in the studied populations is Checker, allelic frequencies ranged from 0.315 for the Checker gene to 0.005 for the Spread marker. Total genetic diversity was moderate, and genetic differentiation between populations was low, accompanied by a high gene flow. An excess of heterozygotes was also observed, and low genetic distance values were found between populations. The results indicate limited genetic differentiation among populations, leading to the conclusion that pigeon populations in Montería are highly related.

In vitro inhibition mechanism of Trichoderma asperellum isolates from corn against Rhizoctonia solani causing banded leaf and sheath blight disease and its role in improving the growth of corn seedlings

BackgroundOne of the primary corn diseases, banded leaf and sheath blight, is carried on by the pathogenic fungus Rhizoctonia solani. Efforts to control R. solani are more directed at environmentally friendly control using a biological control agent, such as Trichoderma spp. as antagonistic agents and plant growth promoter. This study aimed to identify T. asperellum isolates based on molecular characteristics and to determine the in vitro inhibition mechanism against R. solani and its role in enhancing the growth of corn seedlings.ResultsThe HMRP7, HMRF7A, HMEDF1B, HMEDF6A, and CHM01 isolates were identified as T. asperellum with a genetic distance coefficient value of 0.000 and a very high similarity of 100%. Meanwhile, the RsHM isolate was identified as R. solani with a homology level of > 90% and genetic distance coefficient values ranging from 0.000 to 0.032. The antagonistic ability showed that the five T. asperellum isolates were able to inhibit the growth of R. solani in vitro on PDA medium with an inhibition percentage of ≥ 50%, so they were categorized as antagonist agents. T. asperellum showed the antagonistic mechanism in inhibiting the R. solani growth through the action of parasitism. The five T. asperellum isolates tested on corn seedlings showed a significantly high difference from the control treatment on the observational variables of maximum growth potential (MGP), growth rate (GtR), growth simultaneity (GS), vigor index (VI), germination rate (GR), and median germination time (T50).ConclusionCHM01 isolate showed better potential than other isolates in inhibiting the growth of R. solani in vitro on PDA medium with a parasitism mechanism and enhancing the growth of corn seedlings.

Genetic diversity and conservation of Siberian apricot (Prunus sibirica L.) based on microsatellite markers

Siberian apricot (Prunus sibirica L.) is a woody tree species of ecological, economic, and social importance. To evaluate the genetic diversity, differentiation, and structure of P. sibirica, we analyzed 176 individuals from 10 natural populations using 14 microsatellite markers. These markers generated 194 alleles in total. The mean number of alleles (13.8571) was higher than the mean number of effective alleles (6.4822). The average expected heterozygosity (0.8292) was higher than the average observed heterozygosity (0.3178). Shannon information index and polymorphism information content were separately 2.0610 and 0.8093, demonstrating the rich genetic diversity of P. sibirica. Analysis of molecular variance revealed that 85% of the genetic variation occurred within populations, with only 15% among them. The genetic differentiation coefficient and gene flow were separately 0.151 and 1.401, indicating a high degree of genetic differentiation. Clustering results showed that a genetic distance coefficient of 0.6 divided the 10 natural populations into two subgroups (subgroups A and B). STRUCTURE and principal coordinate analysis divided the 176 individuals into two subgroups (clusters 1 and 2). Mantel tests revealed that genetic distance was correlated with geographical distance and elevation differences. These findings can contribute to the effective conservation and management of P. sibirica resources.

Morphological and Genetic Analysis of Momordica cochinchinensis (Lour.) Spreng. (Gac) from Different Accessions in Malaysia

Momordica cochinchinensis or gac fruit is a 'superfruit' that is well-known in Vietnam. Gac is an orange fruit that is ovoid in shape and has a soft spiny texture. In Malaysia, gac fruit is a new and less known plant. This study aimed to characterize gac fruit using morphological analysis involving both vegetative and reproductive parts and to characterize the genetic diversity in gac fruit by using Inter-simple sequence repeat (ISSR) analysis. Four different gac accessions were collected from different areas (Kota Damansara (Selangor), Melaka Tengah (Melaka), Hulu Langat (Selangor) and Kuantan (Pahang)) were cultivated under tropical conditions in Kuantan, Pahang. The gac accessions showed differences in morphological characters. Generally, the gac fruits were reddish-orange in colour, the leaf was dark green on the adaxial part and light green on the abaxial part, and the female and male flower was light yellow and white in color. The fruit weight ranged from 193.72 g (GD) to 334.70 g (GH) with varied shapes and spike density. DNA extraction was following the CTAB method. All 30 primers showed high levels of polymorphism (83%) and the polymorphism information content (PIC) with the mean of 0.48. Nei's genetic distance coefficient ranged between 0.27 and 0.6 with the mean value of 0.41. Dendrogram based on UPGMA analysis grouped the four gac accessions into two main groups. Cluster I consisted of accession GD, GM and GH while cluster II consisted of only GX. Results from both morphological and molecular analysis showed genetic diversities in all four gac fruits studied.

Morpho-physiological and molecular characteristics of bacteria causing stalk rot disease on corn in Gorontalo, Indonesia

Abstract. Suriani, Patandjengi B, Muis A, Junaid M, Mirsam H, Azrai M. 2023. Morpho-physiological and molecular characteristics of bacteria causing stalk rot disease on corn in Gorontalo, Indonesia. Biodiversitas 24: 1749-1758. Stalk rot disease was observed in corn in Gorontalo with typical symptoms, such as soft rot on the stalk, leaf wilting, and plant death. This study aimed to characterize the bacteria causing stalk rot disease in corn. Samples of infected plants were collected and identified morphologically, physiologically, and molecularly. The results showed that nine bacterial isolates were isolated from infected plants. All nine isolates showed positive hypersensitive responses on tobacco leaves. In comparison, only two bacterial isolates (BGO1 and BGO4) were positive on pathogenicity tests on corn. However, the BGO4 isolate caused the highest disease incidence with a faster incubation period. The BGO4 isolate was gram-negative with white-gray colored colonies. Physiological characterization of BGO4 also showed: positive catalase and indole, oxidase negative, fermentative oxidation, caused soft rot on potato, non-fluorescent, and sensitive to erythromycin. In addition, it can grow at 37-40°C and 5% NaCl, producing protease and lecithinase enzymes. The BGO4 also isolates infected rice, corn, sorghum, foxtail millet, celery, and Aloe vera. Morpho-physiology characteristics and diagnostic amplification of DNA by PCR using the Dickeya-specific primers (ADE1/ADE2) showed that the isolate belongs to the genus Dickeya. Further molecular characterization by analysis of the 16S rDNA using universal primer 27F/1497R successfully amplified the DNA band of BGO4 isolate measuring ±1300 bp. Phylogenetic analysis showed that it was in the same group as Dickeya zeae strain MS32 from Taiwan, strain DZ15SB01 (Thailand), and strain HNJF02 (China), with the coefficient of genetic distance ranging from 0.001 to 0.002. This study is the first report of D. zeae infecting corn in Gorontalo.

Genetic Variability of Different Jordanian Almond Prunus Amygdalus L. Landraces Revealed by Morphological Traits and RAPD Markers

The relationship among six Jordanian almond landraces was studied using morphological traits and RAPD analyses. Across six almond landraces studied, nut shape, kernel size, nut length, nut size, and shell length That showed a high level of variation (CV>30%), while kernel length, shell width, internodes length, and nut width showed comparatively low values (CV<20%). Principal component analysis showed that the first five components explained all morphological variation among the landraces investigated. Kernel and nut traits were predominant in the first three components contributing to most of the total variation that existed among landraces. Euclidean distance was used to construct clusters from morphological data which allocated individuals into two main groups with a distance ranging from 5.5 to 10.14. Hajari, Hami Hallo, and Mukhmaly with small fruit sizes composed one main cluster, while the other three landraces (Oga, Fark, and Abu Dabos) with large fruit sizes composed the other main cluster. Out of 62 pre-screened RAPD primers, 12 with reproducible bands and maximum polymorphism were selected for diversity analysis. Seventy-one bands were scored with 28 of them being the polymorphic. Average value of polymorphism/primer ranged from 20% to 74.2%. Nei's genetic distance coefficient ranged from 0.5 to 0.85 with an average of 0.70. Molecular analysis revealed inconsistent separation among the landraces compared with that based on morphological traits. Although landraces found during the screening in the Ajloun area are limited in number, but considerable variation was observed both at morphological and DNA levels indicating that Jordanian almond landraces are rich and valuable genetic materials for almond improvement.

Genetic analysis of diverse castor (Ricinus communis L.) genotypes based on seed related morphometric traits

Diverse source of early genotypes is obligatory for breeding high yielding early castor (Ricinus communis L.) cultivars. One hundred and twenty-five medium duration genotypes including three checks were evaluated for the presence of genetic diversity and variability. Genetic distance, variance components and correlation coefficients were estimated for seven seed related quantitative traits. Significant genotypic differences were observed among the collections for these traits. High heritability and high genetic advance were noticed for seed length, seed breadth, Length/Breadth ratio, shelling percentage, 100 seed weight and seed yield per plant, thus mode of gene action reported was additive. Genetic diversity analysis based on dendrogram, phenogram and circular form grouped the entries into seven groups and it computed inter and intra cluster distance. Principal Component Analysis (PCA) revealed that the first three components cumulatively accounted for 72.57  per cent of the total variation. Seed yield per plant showed significant association with shelling percentage and 100 seed weight. Also, direct effects were high and positive through seed breadth, Length/Breadth ratio and 100 seed weight. The promising genotypes identified (ICIRG 2272103 and RG 1673) and the information generated would be useful for breeding early/medium cultivarsas well to understand the physiological mechanism related to earliness in castor. Keywords: Castor, Multivariate analysis, Correlation, Genetic diversity, Variability

English

The persistent low yield and farmers’ preference of their traditional yam varieties over the improved varieties necessitated this study to verify the adoption status of the released varieties in Nigeria. A total of 48 accessions of white yam (Dioscorea rotundata) were sampled from six states of Ebonyi, Enugu, Benue, Kogi, Nassarawa and Oyo within Nigeria yam-belt and were genotyped for relatedness to four released varieties from the National Root Crops Research Institute (NRCRI), Umudike yam breeding programme, while 14 accessions of water yam (D. alata) were sampled from four states of Benue, Kogi, Nassarawa and Oyo and were also genotyped for relatedness to three released varieties from International Institute for Tropical Agriculture (IITA), Ibadan. A total of 29 alleles were found in 5 sets of primers analyzed for 52 D. rotundata accessions and the number of alleles ranged from 5 (Dald08, SSR 51 and YM 34) to 8 (Dab2E07) with an average of 5.8 per locus. The observed heterozygosity ranged from 0.19 (YM34) to 0.77 (YM30). A total gene diversity of 0.63 according to Nei (1978) genetic distance coefficients was observed among the 52 D. rotundata accessions. Similarly, a total of 37 alleles were observed when 17 D. alata accessions were analysed with the 7 selected sets of primers. An average of 5.29 alleles was observed per locus. The observed heterozygosity varied from 0.47 (Dab2D06) to 0.82 (YM34). A total gene diversity of 0.58 was observed among 17 D. alata accessions according to Nei’ genetic distance coefficients. Cluster analysis showed that the D. rotundata accessions were classified into 8 clusters. While, 17 accessions of D. alata were classified into 4 clusters. There were relationships between some released varieties and farmers accessions and also among the farmers’ accessions from different locations, indicating that farmers might have given a preferred local name to the released varieties.   Key words: Verification, adoption, status, yam, microsatellites-markers.

Population structure analysis to explore genetic diversity and geographical distribution characteristics of cultivated-type tea plant in Guizhou Plateau

BackgroundTea plants originated in southwestern China. Guizhou Plateau is an original center of tea plants, and is rich in germplasm resources. However, the genetic diversity, population structure and distribution characteristics of cultivated-type tea plants in the region are unknown. In this study, we explored the genetic diversity and geographical distribution of cultivated-type tea accessions in Guizhou Plateau.ResultsWe used 112,072 high-quality genotyping-by-sequencing to analyze the genetic diversity, principal components, phylogeny, population structure, and linkage disequilibrium, and develop a core collection of 253 cultivated-type tea plant accessions from Guizhou Plateau. The results showed Genetic diversity of the cultivated-type tea accessions of the Pearl River Basin was significantly higher than that of the cultivated-type tea accessions of the Yangtze River Basin. Three inferred pure groups (CG-1, CG-2 and CG-3) and one inferred admixture group (CG-4), were identified by a population structure analysis, and verified by principal component and phylogenetic analyses. The highest genetic distance and differentiation coefficients were determined for CG-2 vs CG-3. The lower genetic distance and differentiation coefficients were determined for CG-4 vs CG-2 and CG-4 vs CG-3, respectively. We developed a core set and a primary set. The primary and core sets contained 77.0 and 33.6% of all individuals in the initial set, respectively. The primary set may serve as the primary population in genome-wide association studies, while the core collection may serve as the core population in multiple treatment setting studies.ConclusionsThe present study demonstrated the genetic diversity and geographical distribution characteristics of cultivated-type tea plants in Guizhou Plateau. Significant differences in genetic diversity and evolutionary direction were detected between the ancient landraces of the Pearl River Basin and the those of the Yangtze River Basin. Major rivers and ancient hubs were largely responsible for the genetic exchange between the Pearl River Basin and the Yangtze River Basin ancient landraces as well as the formation of the ancient hubs evolutionary group. Genetic diversity, population structure and core collection elucidated by this study will facilitate further genetic studies, germplasm protection, and breeding of tea plants.

Evaluation on Genetic Relationships Among China’s Endemic <i>Curcuma </i>Herbs by SRAP Markers

<i>Curcuma</i> is historically problematic to identify and clear their relationships for cultivar and variety appearance commonly in China. Sequence-Related Amplified Polymorphism (SRAP) marker was used to detect genetic relationships among 10 China’s endemic <i>Curcuma</i> herbs including three Chinese rarely species firstly (<I>C.</I> <i>amarissima</i>, <i>C. flaviflora</i> and <I>C.</I> <i>yunnanensis</i>). The 2-35 polymorphic bands were amplified by each pair of primers, and a total of 1084 polymorphism bands with an average of 11.78 bands were produced by 93 out of 100 pair of primers within 29 accessions. The data were used to construct a dendrogram by means of COMPLETE in NTSYS–pc2.1. The results shown that the genetic distance coefficient varied from 0.12 to 0.53, <i>Curcuma</i> were divided into three groups, the placement of three rarely species were firstly achieved, and partial species might be muti-origin within Chinese <i>Curcuma</i>.

Assessment of genetic variability of passion fruit using simple sequence repeat (SSR) markers

Purple passion fruit (Passiflora edulis Sims) is the third most important fruit crop in Kenya that is produced for both local and export markets. In Uasin Gishu County, passion fruit had recently emerged as an important cash crop for the small-holder farmers. Understanding the structure and diversity of species is very important in plant breeding and in conservation of genetic resources related activities. This study was set out in 2017-2018 to determine the genetic diversity of purple passion fruits genotypes grown in Uasin Gishu County, Kenya using SSR markers. Among the 50 purple passion fruit accessions used in this study, the genetic distance coefficients among accessions ranged from 0.24 to 0.72, with an average of 0.48. The results of STRUCTURE analysis suggested that the 50 accessions could be grouped into five sub-populations. The clustering was based on the unweighted pair-group method of arithmetic averages (UPGMA) where accessions were divided into three major clusters. The UPGMA dendrogram revealed that accessions from identical or adjacent areas were generally, but not entirely, clustered into the same cluster. Comparison of the UPGMA dendrogram and the Bayesian STRUCTURE analysis showed general agreement between the population sub-divisions and the genetic relationships among accessions. Principal coordinate analysis (PCoA) with SSR markers revealed a similar grouping of accessions to the UPGMA dendrogram and STRUCTURE analysis. Analysis of molecular variance (AMOVA) indicated that 16% of the total was attributed to the diversity among sub-populations, while 84% was associated with differences within sub-populations. Overall, there was a considerable amount of genetic variability among passion fruit accessions grown in Uasin Gishu County of Kenya. The study represents the comprehensive investigation of the genetic diversity of passion fruit accessions which would be valuable for germplasm collection, genetic improvement, and efficient utilization.

Estimation of molecular genetic diversity in some indian sugarcane cultivars as revealed by fluorescent rapd markers

The purpose of this study was to estimate the genetic diversity in some cultivars of sugarcane at the DNA level with an efficient, better sensitivity and highly informative PCR based fluorescent random amplified polymorphic DNA (F-RAPD) and capillary electrophoresis techniques. Degenerate RAPD primers were used for yielding best reproducible banding patterns that were generated for 803 discernible and reproducible bands which included 645 polymorphic, 12 mono-morphic and 146 unique bands. The range of coefficient of similarity or genetic distance among sugarcane varieties was 0.25912-0.64111. Based on the genetic distance calculated from 381 alleles generated from 19 sugarcane cultivars, a dendrogram dividing the cultivars into six clusters was made using the UPGMA (unweighted pair group with arithmetic mean) method. This paper reports the results of a study on the genetic diversity of cultivated 19 sugarcane cultivars as revealed by fluorescent RAPD information which would help to conserve the cultivar-specific genetic diversity for the breeding program. The present study also revealed that molecular markers can be successfully utilized for inferring genetic diversity and genetic relationship of sugarcane cultivars more precisely.

Virulence and Molecular Diversity in the Cochliobolus sativus Population Causing Barley Spot Blotch in China.

Spot blotch, caused by the fungal pathogen Cochliobolus sativus, is a limiting factor for barley (Hordeum vulgare) production in northeast China, which causes significant grain yield losses and kernel quality degradation. It is critical to determine the virulence diversity of C. sativus populations for barley resistance breeding and the judicious grouping of available resistance varieties according to the predominant pathotypes in disease epidemic regions. With little information on the barley pathogen in China, this study selected 12 typical barley genotypes to differentiate the pathotypes of C. sativus isolates collected in China. Seventy-one isolates were grouped into 19 Chinese pathotypes based on infection responses. Seventeen isolates were classified as pathotype 3, which has only been identified in China, whereas most (52 of 71) were classified as pathotype 1. All of the tested isolates had low virulence on the North Dakota (ND) durable, resistant line ND B112. Using 22 selected amplified fragment-length polymorphism (AFLP) primer combinations, genetic polymorphism was used to analyze 68 isolates, which clustered into three distinct groups using the unweighted pair group method average with the genetic distance coefficient. No relationship was found between the virulence of isolates and their origins. Isolates of the same pathotype or those collected from the same location did not group into clusters based on the AFLP analysis.

HETEROSIS AND COMBINING ABILITY FOR GRAIN YIELD AND EARLINESS IN ACCESSIONS OFA RICE CORE COLLECTION

Rice has extensive collections of germplasm, but a small fraction of genotypes are used in breeding programs worldwide. This aimed to assess the heterosis and the combining ability for higher grain yield and earliness, and their correlations to genetic distance among accessions belonging to the Embrapa s Rice Core Collection. Crosses were made in complete diallel, without the reciprocals, being phenotyped in generations F2 and F7 for grain yield (GY) and days to flowering (DTF). It were estimated the varietal effect, mean heterosis, varietal heterosis, specific combining abilityand general combining ability (GCA) of the parents in each generation. For the selection of new lines, the combinations involving the genitors with the highest magnitudes and positive effects for GCA were considered more promising for the GY, of which Canela Curta, Maninjau, Epagri 108 and Diamante stood out, and were also the most productive. For the DTF, the genitors with the largest earliness estimates were Araguaia, CT11632, Irat 122, Pratinha Branco and Tox 503. The recommended parameters for estimating GY in F7 generation from the data of the F2 generation were the mean of GY, GCA and the mean Rogers-W genetic distance coefficient. Crosses with Rogers-W distance coefficients above 0.9 showed higher GY and earliness in F7 generation, whereas in F2 the superior crosses were those that showed Rogers-W between 0.7 and 0.89. The above genotypes and the specific combinations identified may lead to new rice cultivars.

Современная популяционная структура европейского анчоуса Engraulis encrasicolus L. (Engraulidae: Pisces) в Чёрном и Азовском морях и история её формирования

Европейский анчоус, или хамса, Engraulis encrasicolus L. — один из наиболее массовых видов рыб в Азово-Черноморском бассейне. E. encrasicolus — политипический вид; в Чёрном и Азовском морях он представлен двумя внутривидовыми формами — черноморским анчоусом (E. encrasicolus ponticus Alex.) и азовским анчоусом (E. encrasicolus maeoticus Pusanov), таксономический статус которых остаётся до настоящего времени неясным. Актуальной задачей является оценка современной популяционной структуры E. encrasicolus и её возможных изменений под воздействием климатических и антропогенных факторов в целях разработки необходимых мер по предотвращению негативных последствий и сохранения ресурсного потенциала вида. Данная работа посвящена изучению современной популяционной структуры европейского анчоуса в Чёрном и Азовском морях и геологических и палеоклиматических условий её формирования, а также оценке возможных изменений с учётом реальных природных и антропогенных факторов риска. В основу работы положены результаты изучения внутривидовой морфобиологической, биохимической, генетической и экологической изменчивости E. encrasicolus, а также пространственных и репродуктивных взаимоотношений азовского и черноморского анчоуса. В историческом аспекте выполнен анализ литературных данных по проблеме внутривидовой неоднородности E. encrasicolus в Чёрном и Азовском морях, полученных отечественными и зарубежными авторами за 100-летний период (1913–2014); список публикаций включает более 40 наименований. В работе использованы также результаты собственных исследований. Систематизированы и обобщены сведения о границах репродуктивных ареалов черноморского и азовского анчоуса. Установлено, что их репродуктивные ареалы охватывают всю акваторию Чёрного и Азовского морей и перекрываются на всём пространстве. При отсутствии отдельных, пространственно обособленных репродуктивных ареалов и при наличии одновременного нереста принадлежность черноморского и азовского анчоуса к разным подвидам (географическим расам) исключается. Популяционный уровень различий между черноморской и азовской хамсой подтверждают результаты генетико-биохимических исследований: коэффициенты генетического сходства и генетического расстояния между ними составили 0,9983–0,9985 и 0,0015–0,0017 соответственно. Представлена геологическая история формирования популяционной структуры Engraulis encrasicolus. Современные азовский и черноморский анчоусы в прошлом были пространственно разобщены и вступили в контакт лишь вторично (после того как в процессе эволюции между ними возник ряд различий). Их изоляция произошла в миоцене (23,0–5,3 млн лет назад), в новообразованном, изолированном от океана Тетис Сарматском море. В результате возникли две географически обособленные и независимые группы анчоусов (западная и восточная), дальнейшее развитие которых происходило с разной скоростью. Более быстрые темпы эволюции западной группы привели к образованию более прогрессивных черноморского и средиземноморского анчоусов, а более низкие темпы эволюции восточной группы — к образованию более примитивного азовского анчоуса. Только в современную эпоху, после окончания последнего ледникового периода и восстановления связи Чёрного моря со Средиземным 7–5 тыс. лет назад, произошёл контакт между ними, который впоследствии сопровождался гибридизацией, то есть образованием зоны вторичной интерградации. В условиях интрогрессивной гибридизации в последние десятилетия, связанной с осолонением Азовского моря в результате хозяйственной деятельности человека, существует реальная угроза разрушения генофонда азовской хамсы и её «генетического поглощения» черноморской. Тем не менее генетическая идентичность азовского анчоуса до настоящего времени сохраняется. Это происходит прежде всего благодаря экологическим механизмам сезонной (выбор времени) и биотопической (выбор места) изоляции в репродуктивный период. Установлена определённая закономерность перераспределения самок в составе нерестового стада: доля самок азовского анчоуса уменьшается, доля самок черноморской хамсы увеличивается. Из этого следует, что популяции азовского и черноморского анчоуса являются «температурными» расами, адаптированными к разным репродуктивным температурным условиям: азовская — к более низким, черноморская — к более высоким. Кроме сезонной, установлена биотопическая изоляция черноморской и азовской хамсы. Черноморский анчоус предпочитает нереститься в открытых районах Чёрного моря при солёности воды выше 16 ‰: там его доля составляет 55–60 % (в прибрежных водах значение показателя не превышает 5–40 %). Азовский анчоус, напротив, в нерестовый период преобладает в прибрежных опреснённых водах с солёностью ниже 15 ‰: его доля здесь достигает 60–90 %.

Elit Domuz Ayrığı (Dactylis glomerata L.) Genotiplerinde Genetik Çeşitliliğin SSR Markörleri ile Belirlenmesi

Domuz ayrığı (Dactylis glomerata L.) yaygın olarak yetiştiriciliği yapılan, ekonomik açıdan önemli çok yıllık bir buğdaygil yem bitkisidir. Bu araştırma, Ege Tarımsal Araştırma Enstitüsü yem bitkileri ıslah programı kapsamında geliştirilen elit domuz ayrığı klonlarının akrabalık derecelerini ve genetik çeşitliliğini belirlemek amacıyla yürütülmüştür. Çalışmada 32 genotip ve 24 SSR primeri kullanılmıştır. Moleküler analiz sonucunda SSR primerleri toplamda 126 allel üretmiştir. Allel sayısı 3 ila 7 arasında değişmiş ve lokus başına düşen ortalama allel sayısı 5,25 olarak bulunmuştur. Elde edilen allel büyüklükleri ise 101 bp ile 354 bp arasında değişmiş ve polimorfizm oranı her primer için %100 olarak gerçekleşmiştir. Bireyler arasında uzaklık derecesi Jaccard genetik uzaklık katsayısı kullanılarak elde edilmiş ve 0,21 ile 0,84 arasında değişmiş ve genetik çeşitlilik seviyesi yüksek bulunmuştur. Genotiplerden elde edilen 126 allelin 28‘nin nadir alleller olduğu ortaya çıkmıştır. Jaccard genetik uzaklık katsayısı kullanılarak yapılan neighbor-joining analizi sonucunda oluşturulan dendrogram 3 ana gruba ayrılmıştır. A grubu en büyük grubu oluşturmuş ve bünyesinde 15 genotip barındırmıştır. B grubu orijini aynı bölge olan 13 genotiple ikinci büyük grubu oluşturmuştur. C grubu ise en küçük grup olup orijini Türkiye‘nin kuzeyi olan genotipleri barındırmıştır. Moleküler analizler domuz ayrığı genotiplerinin önemli derecede genetik varyasyon taşıdığı ve ıslah programı için değerli kaynaklar olduğu ortaya çıkmıştır. Bunlara ek olarak, SSR tekniğinin domuz ayrığı genotiplerini moleküler olarak tanımlamada oldukça uygun ve etkili bir teknik olduğu sonucuna varılmıştır.

Morphological and Molecular diversity studies in Gossypium hirsutum

Cotton is one of the most important fibre crops of India. India is having highest cotton growing area however; its production per unit area is low and stagnant owing to several biotic and abiotic stresses. In order to increase productivity, high yielding, biotic and abiotic stress resistant hybrid/variety need to be developed. Hence, an attempt was made to assess the relationship between heterosis and genetic diversity. Identifying the best genotype combinations for the development of commercial hybrids of cotton remains the main challenge to cotton breeders. Genetic diversity of thirteen parents and heterosis in their forty hybrids which were developed by crossing 8 elite Lines with 5 carefully selected Testers in L × T fashion were used to assess the relationship between heterosis and genetic diversity for eleven important yield and yield contributing traits and three fibre related traits in intra hirsutum cotton (Gossypium hirsutum L.). Diversity studies were conducted by using both Mahalanobis D2 statistic and by random 60 SSR markers, which inferred medium genetic diversity between parents. Correlation coefficient of genetic distance with F1 mean performance, mid, better parent heterosis and specific combining ability for all studied traits were statistically non-significant, indicating that prediction of heterosis for complex traits based on these two genetic diversity estimates is difficult.

Genetic Variation at 15 Autosomal STR Loci Among Seven Egyptian Populations.

Egypt is a transcontinental country containing substantial ethnic, cultural, and linguistic diversity among its people. This study was conducted to investigate the genetic variation at 15 AmpFlSTR Identifiler short tandem repeat (STR) loci, D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, and FGA, within and between seven Egyptian populations. Samples of 814 unrelated individuals from Northern Coast, Delta, Greater Cairo, Canal governorates, Northern Upper Egypt, Southern Upper Egypt, and Sinai were investigated. All loci were highly polymorphic in all sample populations. The data were analyzed to give information on allele frequencies and other population statistical parameters. After applying Bonferroni correction, the agreement with Hardy-Weinberg equilibrium (HWE) was confirmed for all loci (exact test), and for all loci with the exception of D3S1358, D19S433, and D18S51 (X2 test). The levels of genetic differentiation and the genetic relationships among populations were evaluated by coefficient of genetic differentiation (FST), AMOVA, and genetic distance of Nei. The most differentiated populations were found between Sinai and Southern Upper Egypt. These two populations showed the lowest within-population variation, whereas the population of Greater Cairo showed the highest within-population variation as indicated by the fixation index FIS. The varying levels of genetic relatedness among the populations in relation to their geographical distribution were analyzed using Mantel test. The results demonstrated that the effectiveness of STR markers enhances their value for identifying the genetic variation within and between Egyptian populations.

Genetic diversity and relationship of sainfoin (Onobrychis viciifolia Scop.) germplasm as revealed by amplified fragment length polymorphism markers

Sainfoin (Onobrychis viciifolia Scop.) is a perennial forage legume widely distributed in the northern temperate regions of the world. Its genetic improvement has been relatively slow due, in part, to the lack of genetic information including molecular characterization of sainfoin germplasm. An attempt was made to evaluate genetic diversity and relationships among 38 sainfoin accessions collected from different regions of the world using amplified fragment length polymorphism (AFLP) markers. Five AFLP primer pairs were used to assess 367 individual plants, which produced 1042 polymorphic AFLP bands. The frequencies of the scored bands in all assayed individuals ranged from 0.003 to 0.973, with a mean value of 0.165. The analysis of molecular variance revealed higher within-accession (84.3%) genetic variation than among accessions (15.7%). The genetic distance based on inter-accession distance matrices was significant for most accessions but was not significant for accessions sharing similar parents. A dendrogram of the collected accessions showed two clusters at an inter-accession genetic distance coefficient of 0.36. The revealed information on genetic distance and genetic diversity of the sainfoin accessions is useful for selecting genetically diverse germplasms for sainfoin genetic improvement efforts.

Microwave treatment can induce chrysanthemum phenotypic and genetic changes

Abstract The impact of microwaves on the DNA of plant cells is still ambiguous, but the usage of this electromagnetic radiation as a source of variation in mutation breeding could be very advantageous. The aim of the study was to examine the influence of microwave radiation on the in vitro regeneration and acclimatization efficiencies, as well as on the genetic and phenotypical variation of chrysanthemum ‘Alchimist’. Leaf explants with or without callus were subjected to microwave treatment for various periods and in different milieus. Microwaves were generated by a domestic magnetron at 2.45 GHz, 800 W·cm−2. Irradiation negatively affected shoot formation if applied for longer periods. On the other hand, it did not affect the rooting and acclimatization steps which were fully successful. Chrysanthemums produced from MW-treated explants had longer shoots with inflorescences of greater diameter and altered phenotypes. It was also noticed, that MW-treatment affected the generative phase by prolonging the bud colouration period. The evaluation of genetic variation was performed with the RAPD technique by using 10 primers for all regenerated shoot; a total of 116 genotypes were analysed. Approximately 22% of plants regenerated from MW-treated explants showed band profiles different from the reference control. Most plants (86%) with altered band profiles originated from irradiated callus. These plants also showed higher mean genetic distance coefficient. In conclusion, microwaves can be considered as an efficient and easy-to-access tool in mutation breeding of chrysanthemum ‘Alchimist’.