Genetic Diversity in Populations of Mediterranean Fruit Flies in North-Eastern Brazil

This study aimed at determining the population genetic structure of Mediterranean fruit flies (Ceratitis capitata) in North-eastern Brazil, so as to improve our understanding of the viability of the inter-simple sequences repeat (ISSR) markers in Brazilian populations, along with inferences on population genetic composition which can be used in management programs. For this, ISSR markers were used in groups collected from four municipalities in this region. Primers were polymorphic, revealing moderate expected heterozigosity, with 80% of the variation occurring within populations and moderate structure. Bayesian analysis revealed K = 3, consistent with pairwise FST and indicating low structure between Barra do Choça and Planalto, and moderate structure between Caraíbas and Planalto. Data indicated high diversity, suggesting two interpretations: the analyzed populations arose from a single population and are now under structuring processes, or populations had different origins, but are currently connected by gene flow. Thus, ISSR primers were affective in obtaining information about genetic structure of C. capitata populations in North-eastern Brazil, as evidenced by high polymorphism and separation or grouping of populations according to their allelic compositions. Furthermore, this paper provides useful information for understanding the genetic diversity, population structure and gene flow of C. capitata populations in this region and developing regional strategies for the control and management of the species.

ASSESSMENT OF ECOLOGICAL AND GENETIC DIVERSITY OF THE GENUS VIGNA SAVI USING BIOTECHNOLOGICAL METHODS - ISSR MARKERS

The world's genetic resources of plants are the main source of improving crops for decades to come. The gene pool of plants has a hidden resource of new genes, or their combinations, including - selection-important features. The study of the potential of the plant gene pool with the main biological and economic characteristics allows to expand the genetic base of crops for the successful implementation of breeding programs in various areas. The genus Vigna has about 200 species that are grown in warm regions of the planet. The centers of origin of the species are in Africa, but mung beans, urd, azuki and rice beans are of Asian origin. The collection includes 20 specimens belonging to 7 species of the genus Vigna: V. aconitifolia (Jacq.) Marechal (willow aconitolista, mott) – 3 specimens, V. angularis (Willd.) Ohwi et Ohashi (adzuki) – 4, V. radiata (L.) R. Wilczek (mash) – 4, V. umbellata (Thunb.) Ohwi et Ohashi (vigna rice) – 4, V. unguiculata (L.) Walp. (Chinese) – 5. These are mainly local varieties, about 10 % are breeding varieties and 1% are forms that grow in nature. The multifaceted use of cultivated species of the genus Vigna contributed to their spread throughout the tropical, subtropical and temperate zones of the globe. They are economically important crops in many developing countries. Geographical analysis showed that most of the samples came from the areas of world agriculture and crop formation. most samples of V. radiata, V. mungo, V. aconitifolia, V. trilobata, V. umbellata were obtained from India and Pakistan, V. angularis – from East Asia and China, V. unguiculata – East Africa (Ethiopia, Kenya), V unguiculata – from China. However, the exact place of domestication of this culture has not been established, and in numerous sources of literature can be found different opinions of scientists on the origin of cowpea and the centers of its diversity. Recently, using the methods of molecular genetics (RAPD, AFLP and others) it was confirmed that the northern part of Africa is the center of origin of the cultured, because the wild types of West Africa are closer to cultural forms than the wild types of East and South Africa. It should be noted that the species of cowpea have a significant intraspecific polymorphism. The samples showed strong variability of morphological and economically valuable features. Such a wide range of variable variability is due to the places of cultivation of samples, different environmental conditions (plains, mountains, climate). According to the results of the evaluation of the DNA polymorphism of cowpea using molecular genetic markers, it was found that the species of cowpea involved in the study are characterized by a high level of DNA polymorphism, which averaged 78.6 %. 145 loci were identified, including 31 unique, specific to a particular sample, and 31 monomorphic, characteristic of all samples. Monomorphic loci are conserved regions of DNA that indicate the common origin of the species of cowpea involved in the work, and can be used as genus and species-specific markers. Unique loci indicate genetic divergence of the studied material and can serve as markers of certain samples. The average level of intrapopulation polymorphism of cowpea DNA (37.2–93.8 %, depending on the genotype) was established, which indicates the existence of significant variability in the studied samples of cowpea. It shows a high level of genetic divergence of cowpea species and testifies in favor of the polyphyletic theory of their origin.

Evaluation of Achillea, Matricaria, and Anthemis plants following selection for drought tolerance at seedling stages

The genetic potentials of eight species of Achillea (A. millefolium, A. fillipendulla, A. biebersteinii, A. nobilis, A. eriophora), Matricaria (M. ricotita), and Anthemis (An. haussknechtii and An. tinctoria) under drought conditions during the seedling stage were measured. Non-ionic water-soluble polymer polyethylene glycol (PEG, molecular weight 6000) was used to simulate water stress at five osmotic potential levels (0, –0.3, –0.6, –0.9, and –1.2 MPa). An acceptable threshold value for germination was osmotic potential –0.6 MPa, and the modest osmotic potential was –1.2 MPa for studied taxa. Seedlings of germinated at two control and osmotic potential –0.6 MPa (as an acceptable threshold value for germination) treatments were sowed in a field under rainfed conditions. Genetic differentiation of control plants (CP) versus early selected plants (ESP, germinated at osmotic potential –0.6 MPa) was studied using morphological, physiological, and molecular (ISSR) markers. No significant differences were observed between morphological traits of CP and ESP in all species, however, days to full flowering shortened in ESP. The physiological results demonstrate that under rainfed conditions, the ESP, in a quick response, collect osmolytes and amplify the activity of antioxidative enzymes to survive drought. The genetic relationship in the group of genotypes, that ISSR marker set it out, is affiliated to taxon even though AMOVA showed a partial differentiation between CP and ESP groups (21%). It was concluded that the selection of tolerating individuals at the seedling stage represents a likely positive strategy to have higher drought tolerance feature in plants under rainfed conditions.

Analysis of genetic diversity in selected sugarcane (Saccharum officinarum L.) accessions using inter simple sequence repeat (ISSR) markers

<p class="042abstractstekst"><span lang="EN-US">Genetic diversity information among a population is important in exploiting heterozygosity for the improvement of crop species through breeding programmes. This study was therefore, conducted to assess genetic diversity and establish molecular relationships among 20 selected exotic sugarcane accessions from the Unilorin Sugar Research Institute germplasm using Inter Simple Sequence Repeat (ISSR) molecular markers. Genomic DNA was extracted from the sugarcane leaf. Fragments amplification was then performed by polymerase chain reaction (PCR) with ISSR markers and the data obtained were analyzed using MEGA 4 software. Analysis of the electropherogram showed a total of 39 loci consisting of 369 bands, out of which 95.8% were polymorphic. The biplot analysis showed all the markers contributed to the observed diversity with the least achieved with ISSR6. The principal co-ordinate analysis grouped the accessions into four clusters, comprising mixtures of all the six collection sites. The polymorphism obtained in the present study showed that the ISSR markers are effective for assessment of genetic diversity of the sugarcane accessions as it reveals the genetic similarity or divergence of the accessions regardless their place of origin or cultivation.</span></p>

Androgenesis—Technology for Obtaining Genetically Stable Breeding Material of Capsicum annuum L.

Androgenesis in vitro is a basic method of obtaining haploid plants and DH (doubled haploid) lines of major crops such as potato, rapeseed, tomato, pepper, wheat, maize, and barley, and also many different minor crops and species with lower agricultural impact. Diploid plants appearing among androgenic regenerants are the effect of spontaneous doubling of the chromosome number in haploid cells during an embryo’s early developmental stages and are valuable fully homozygous breeding material. The subject of the presented research is spontaneous diploidization occurring in the development of androgenic, haploid pepper regenerants. In the presented experiment, the formation of diploid seeds was observed in the progeny of an androgenic, haploid plant derived in an anther culture of a hybrid (Capsicum annuum L. ATZ × Capsicum annuum L. `Corno di toro`)F2. Agromorphological and molecular analyses concerned eight diploid plants being progeny of the anther-derived haploid regenerant. Five of the plants constituted a phenotypically balanced group with valuable agromorphological features. Their genetic homogeneity was confirmed using 10 RAPD markers and 16 ISSR markers. Based on the results, it was concluded that anther-derived haploid plants of Capsicum can be the source of diploid, apomictic seeds, and the obtained offspring may constitute genetically stable, valuable breeding material.

Molecular identification and genetic relationships among Alcea (Malvaceae) species by ISSR Markers: A high value medicinal plant

Alcea L. is one of the largest genera of Malvaceae family with nearly 70 species worldwide mainly distributed in SW Asia. According to the latest revision of the family, it is represented by 34 species in the Flora of Iran, among them, 15 species are endemic. It is tough to accurate germplasm/ plant recognition by using morphological characteristics because of its propagation, growing and using. We conducted a molecular data analysis on these plant species due to their importance. We examined 156 plants from 14 species in 16 regions that were selected randomly for this investigation. It has been 119 polymorphic bands (94.33%) were resulted from 128 bands of 10 primers in amplification of genomic DNA. ISSR primers have a great capacity to detect polymorphic loci among Alcea species, as evidenced by the high average PIC and MI values found. The genetic similarity of 14 species was calculated and ranged between 0.635 to 0.990. Inter-Simple sequence repeats (ISSR) markers research revealed that Alcea tarica Pakravan & Ghahreman and Alcea kopetdaghensis lljin had the least similarity, while Alcea semnanica Pakravan and Alcea mazandaranica Pakravan & Ghahreman had the most. The current study attempts to answer three questions: 1) can ISSR markers identify Alcea species? 2) what is the genetic structure of these taxa in Iran? and 3) what is the inter-relationship between these taxa? The current study discovered that ISSR markers can be used to identify species.