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.

A Review on In-vitro Haploid Production in Orchids

The aim of writing this paper is to review production of haploids in orchids in vitro. Haploids possess half number of chromosomes and do not undergo fertilization. In vitro conditions provide necessary nutrients and conditions that are required for growth of haploid plantlets. The natural breeding cycle of orchids is very slow as well as unpredictable. To reduce this time, the technique of in vitro haploid production is used. In vitro conditions can decrease or shorten the time required for juvenile period in Orchids. Haploid plants are produced from in vitro haploid culture. This technique is useful to produce homozygous pure lines and to increase the yield of a plant.

Creation of an interspecific hybrid of Capsicum annuum L. and C. frutescens L. using biotechnological approaches

Relevance. Pepper is a common crop both for fresh consumption and for the preparation of spices. Recently, along with the increasing popularity of C. annuum L. pepper, there is increasing interest in other species of this genus, which have a number of breeding and important properties. The most important method of enriching the gene pool of cultivated plants is distant hybridization, through which valuable traits are transferred from wild species to cultivated ones. The development of a new variety is a lengthy process, stretching over several years. In this regard, breeders have faced the challenge of obtaining pure lines to create a pepper hybrid with desired properties by applying modern biotechnological methods that will accelerate this process. One of them is the method of microspore culture, which allows mass production of haploid plants, reducing the time for creating constant parental lines.Material and methods. The aim of the work was to create an interspecific hybrid of hot pepper (C. annuum L. x C. frutescens L.) with high ornamental properties, a complex of economically valuable traits, with good taste qualities. The research was carried out in the film greenhouse of FSBSI FSVC in the Moscow region. The research material was a variety population of hot pepper Capsicum frutescens Cz-544-14, used as a paternal line, which was heterogeneous, and a pure line of C. annuum L. (Pb-551) created by classical breeding.Results. The pepper hybrid F1 Christmas bouquet was created as a result of hybridization of species parental forms obtained by different methods (biotechnological and classical). To accelerate the production of an aligned paternal form of C. frutescens L., the technology of doubled haploids through microspore culture was used. As a result, doubled haploid plants meeting the planned model (compact low habit, purple fruit colouring in technical ripeness and red in biological ripeness) were obtained. The resulting hybrid combined all the necessary economic features: high ornamentality, compactness, bouquet arrangement of fruits, high taste and aroma. Thus, the use of remote interspecific hybridization in the breeding process in combination with biotechnological approaches can accelerate the production of new forms of hot peppers that meet the demands of the market.

Production of haploid embryos and plants in Iranian melon (Cucumis melo L.) through irradiated pollen-induced parthenogenesis.

The irradiated pollen technique (IPT) is the most successful haploidization technique within Cucurbitaceae. The influence of gamma-ray doses (250, 350, 450 and 550 Gy), genotypes and stage of development of embryos obtained by IPT on the induction of haploid embryos were studied in several Iranian melon cultivars as well as their hybrids with alien cultivars. Female flowers were pollinated using pollen that had been irradiated with gamma rays. Different shapes and stages of embryos were excised 21-25 days after pollination and cultured on E20A medium. Direct culture, liquid culture and integrated culture methods were used; integrated culture and liquid culture methods showed advantages in increasing the efficiency of haploid plant production in melon breeding programmes. Results revealed that 550 Gy of gamma irradiation was successful in inducing parthenogenesis and fruit development, whereas lower irradiation doses were not effective in inducing haploid embryos. The percentages of embryos per seed were the highest in 'Samsoori' (1.2%) and 'Saveh' (1.1%) cultivars. Some of the heart-shaped and cotyledon-shaped embryos developed into haploid plants. In total, 52 parthenogenic melon plantlets were recovered from 274 embryos via IPT. Production of haploid embryos and haploid plants was strongly influenced by gamma-ray dose, embryo stage and genotype. Indirect methods and chromosome counting performed on the root cells of regenerated plants showed that these plants were haploid (n = x = 12).

Effect of Chemical Composition of Nutritive Medium and Explant Size Over Androgenetic Response in Microspore Culture of Brassica oleracea L.

The dimension of the bud is a key factor for the orientation of microspore culture and the success of obtaining double haploid plants as it is a strong correlation between bud size and the developmental stages of microspores, and it is specific for each plant species and genotype. Our study was focused to determine the correlation between morphological characteristics, namely floral bud size and specific microspore developmental stages in order to determine the proper size, suitable for a successful protocol of obtaining double haploid plants in Brassica oleracea var. italica. Thus, we tested four bud sizes ranging from 2.0 to 4.0 mm measured from the base to the tip of the bud. After the statistical analysis of the results it can be emphasized that the best results were obtained in the case of using as a source of microspores the flower buds with the size between 3.1-3.5 mm. At this dimension, the share of microspores in the uninucleate stage, predominantly in the late uninucleate stage, is 90%, thus ensuring a homogeneous population of microspores in the optimum stage of development. Their evolution is predominantly embryogenic, the percentage of microspores following the gametophytic pathway is reduced, by only 9.12%.