scholarly journals Overview of Biotic Stresses in Pepper (Capsicum spp.): Sources of Genetic Resistance, Molecular Breeding and Genomics

2020 ◽  
Vol 21 (7) ◽  
pp. 2587 ◽  
Author(s):  
Mario Parisi ◽  
Daniela Alioto ◽  
Pasquale Tripodi

Pepper (Capsicum spp.) is one of the major vegetable crops grown worldwide largely appreciated for its economic importance and nutritional value. This crop belongs to the large Solanaceae family, which, among more than 90 genera and 2500 species of flowering plants, includes commercially important vegetables such as tomato and eggplant. The genus includes over 30 species, five of which (C. annuum, C. frutescens, C. chinense, C. baccatum, and C. pubescens) are domesticated and mainly grown for consumption as food and for non-food purposes (e.g., cosmetics). The main challenges for vegetable crop improvement are linked to the sustainable development of agriculture, food security, the growing consumers’ demand for food. Furthermore, demographic trends and changes to climate require more efficient use of plant genetic resources in breeding programs. Increases in pepper consumption have been observed in the past 20 years, and for maintaining this trend, the development of new resistant and high yielding varieties is demanded. The range of pathogens afflicting peppers is very broad and includes fungi, viruses, bacteria, and insects. In this context, the large number of accessions of domesticated and wild species stored in the world seed banks represents a valuable resource for breeding in order to transfer traits related to resistance mechanisms to various biotic stresses. In the present review, we report comprehensive information on sources of resistance to a broad range of pathogens in pepper, revisiting the classical genetic studies and showing the contribution of genomics for the understanding of the molecular basis of resistance.

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 564
Author(s):  
Gaetano Distefano

The main challenges for tree crop improvement are linked to the sustainable development of agro-ecological habitats, improving the adaptability to limiting environmental factors and resistance to biotic stresses or promoting novel genotypes with improved agronomic traits [...]


2011 ◽  
Vol 9 (01) ◽  
pp. 97-108 ◽  
Author(s):  
H. D. Upadhyaya ◽  
K. N. Reddy ◽  
Shivali Sharma ◽  
R. K. Varshney ◽  
R. Bhattacharjee ◽  
...  

Pigeonpea (Cajanus cajan(L.) Millsp. is one of the most important legume crops as major source for proteins, minerals and vitamins, in addition to its multiple uses as food, feed, fuel, soil enricher, or soil binder, and in fencing, roofing and basket making. ICRISAT's genebank conserves 13,632 accessions of pigeonpea. The extensive use of few parents in crop improvement is contrary to the purpose of collecting a large number of germplasm accessions and has resulted in a narrow base of cultivars. ICRISAT, in collaboration with the Generation Challenge Program, has developed a composite collection of pigeonpea consisting of 1000 accessions representing the diversity of the entire germplasm collection. This included 146 accessions of mini core collection and other materials. Genotyping of the composite collection using 20 microsatellite or simple sequence repeat (SSR) markers separated wild and cultivated types in two broad groups. A reference set comprising 300 most diverse accessions has been selected based on SSR genotyping data. Phenotyping of the composite collection for 16 quantitative and 16 qualitative traits resulted in the identification of promising diverse accessions for the four important agronomic traits: early flowering (96 accessions), high number of pods (28), high 100-seed weight (88) and high seed yield/plant (49). These accessions hold potential for their utilization in pigeonpea breeding programmes to develop improved cultivars with a broad genetic base. Pigeonpea germplasm has provided sources of resistance to abiotic and biotic stresses and cytoplasmic-male sterility for utilization in breeding programmes.


Author(s):  
Ramakrishna Swarnapriya

In vegetables the factors for biotic stress are pests, diseases and nematodes. The damages induced by these factors reflect highly on production, productivity and quality. Although application of pesticides/fungicides and nematicides has managed these stresses, excessive use of unsafe chemicals results in environmental pollution and leave residues in vegetables which are above threshold levels and also promote the development of new races/biotypes of pests and pathogens. Therefore vegetable improvement works concentrate on high yielding varieties with multiple resistance to these biotic stresses. For such studies, the knowledge on the genetic basis of resistance and plant-pest/pathogen interactions is necessary which will in turn improve the efficiency of the breeding programmes by introducing resistant genes and result in high-yielding genetically resistant cultivars. For the development of resistant varieties and pre-breed lines, information on sources of resistance is prerequisite and serve as a backbone in the breeding programme. Further, gene action responsible for the inheritance of characters helps in the choice of suitable breeding methods for the improvement of the crop. Work has been done by using the various breeding methods and resistant varieties have been bred and they offer the cheapest means of pest/disease/nematode control. Resistant varieties obviate the use of chemicals, thus reduce environmental pollution and facilitate safe food for human consumption.


2016 ◽  
Vol 8 (4) ◽  
pp. 156 ◽  
Author(s):  
Brhan Khiar Saleh ◽  
Remmy W. Kasili ◽  
Edward G. Mamati ◽  
Woldeamlak Araia ◽  
Aggrey B. Nyende

<p>Diversity in plant genetic resources provides an opportunity for plant breeders to develop new and improved cultivars with desirable characteristics. The purpose of this study was to assess the diversity of Eritrean pepper germplasm in order to obtain information for improving it. A total of 60 pepper (<em>Capsicum</em> spp.) seed sample collections were obtained from farmers and institutions in Eritrea. The collections were evaluated at two sites located in two different agro-climatic regions of the country. The collections were assessed using 16 quantitative and 23 qualitative descriptors. A Randomized Complete Block Design was used for the evaluation. Quantitative and qualitative data of the two sites were subjected to Principal Component Analysis, Principal Coordinate Analysis, Hierarchal clustering, Analysis of variance and Correlation. The distribution of characters of the different quantitative and qualitative traits and the performance of the collections showed the existece of variable characters distributed among the collections indicating considerable diversity. For quantitative variables, the first three components were able to explain 61%, 58% and 67% of the total variation in Hamelmalo, Asmara and combined data of the two sites respectively. While for the qualitative variables the first three components were able to explain a variation of 58% in Hamelmalo, 49%, in Asmara and 55% combined data of the two sites. Phenological attributes and fruit characteristics were found to contribute more to the variation. The majority of the traits evaluated were significant and the highest Coefficient of Variation was related to fruit characteristics. The results of this study showed that there is sufficient variability within the Eritrean pepper genotypes that could be used in future breeding and crop improvement programs.</p>


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 501
Author(s):  
Carlos Rial ◽  
Rosa M. Varela ◽  
José M.G. Molinillo ◽  
Sara Peralta ◽  
Francisco A. Macías

Several strategies have been proposed to control parasitic plants and these include biological control, the use of herbicides, and suicidal germination or trap crops. In the case of sunflower, the most effective solution is genetic resistance. Nevertheless, the use of resistant cultivars is followed by the appearance of new and more virulent races of the parasite that overcome the existing sources of resistance. For this reason, it is necessary to increase our knowledge of the mechanisms involved in the resistant varieties. In this study, the presence of compounds involved in pre-attachment resistance mechanisms in sunflower varieties was analyzed. The production of stimulators of the germination of parasitic plant seeds and the concentration of the haustorial elongation inhibitor, scopoletin, were measured in exudates of resistant and susceptible sunflower varieties. It was found that dehydrocostuslactone and orobanchyl acetate are not involved in the resistance of the sunflower varieties studied. The results demonstrate that costunolide, heliolactone, and scopoletin are related to sunflower resistance. The sunflower varieties studied do not use all available options to fight parasitic plants. This could be one of the reasons that sunflower resistance is rapidly overcome by broomrape.


2018 ◽  
Author(s):  
V  Leunov ◽  
Y  Mikheev

Расширение ассортимента потребляемых овощных культур – одна из основных задач в селекционно-семеноводческой работе с редечными культурами на Дальнем Востоке. В статье приводятся данные о селекции редечных культур (лобы, дайкона, редьки и др.) на Приморской овощной опытной станции. В результате проведения многолетних исследований и реализации ряда научных программ был создан новый исходный материал для селекции. В настоящем материале также подведены итоги актуальных направлений в селекции редечных культур в условиях муссонного климата. Селекционно-семеноводческие исследования в условиях климата Дальнего Востока с использованием индивидуального, а также индивидуально-семейственного методов отбора, разработка и внедрение технологических приемов первичного и сортового семеноводства обеспечили создание перспективного селекционного материала. Выделены ценные генисточники для создания новых сортообразцов китайского, японского и европейского подвидов редьки с высокими иммунологическими, продуктивными и товарными качествами, повышенными биохимическими показателями, высокой устойчивостью к переувлажнению почвы и возбудителями болезней. Созданы и включены в Госреестр РФ высокопродуктивные сорта китайского подвида редьки (лоба) Малиновый шар и Золотой рог, европейского подвида зимней редьки Ночная красавица, устойчивые к переувлажнению почвы и цветушности, бактериальным заболеваниям. В результате более чем двадцатилетних исследований изучены морфологические и биологические особенности формирования семенных растений редьки, использование эффективных элементов отбора в сочетании с агротехническими приемами возделывания. Усовершенствованы технологические методы первичного и товарного семеноводства редьки, выделены благоприятные агроклиматические зоны выращивания семенных растений, способствующие получению высококачественных семян при сохранении ими высоких биологических и хозяйственных признаков. Для условий муссонного климата Дальнего Востока внедрена в производство система первичного и сортового семеноводства редьки с использованием пересадочной и беспересадочной технологии выращивания. Результаты работы открывают дорогу к созданию новых высокоурожайных российских сортов и гибридов редечных культур.Expansion of the range of consumption of vegetable crops is one of the main tasks in the breeding and seed work with regions cultures in the Far East. The article presents data on the breeding radishes cultures (loba, daikon, radish, etc.) on the Maritime vegetable experiment station. As a result of years of research and implementation of a number of research programs has created a new source material for breeding. In this paper also summarize the current trends in the selection of radishes cultures in conditions of monsoonal climate. Breeding and seed research in the climate conditions of the Far East with the use of individual and individual and family methods of selection, development and implementation of technological methods of primary and varietal seed production ensured the development of advanced breeding material. Allocated valuable genitocracy to create new varieties of Chinese, Japanese and European subspecies of radishes cultures with high immunological, productive and commercial qualities, elevated biochemical parameters, high resistance to waterlogging and soil pathogens. Created and included in the state register of the Russian Federation high-yielding varieties of Chinese subspecies of radish (loba) a Crimson ball and the Golden horn, the European subspecies winter radish Night beauty, resistant to waterlogging of the soil and bolting and bacterial diseases. As a result of more than twenty years studied the morphological and biological peculiarities of formation of seed plants of radishes, the use of effective elements of selection in combination with agrotechnical methods of cultivation. Improved technological methods of primary and commercial seed radishes allocated to favorable agro-climatic zones of cultivation of seed plants, which would produce high-quality seeds while preserving their high biological and economic characteristics. For the conditions of monsoon climate of the Far East implemented in the production system of primary and varietal seed radishes using transit and non-stop growing technologies. The results of this work open the way to the creation of new high-yielding Russian varieties and hybrids of radishes cultures.


Author(s):  
R. E. Kazakhmedov ◽  
М. А Magomedova

One of the modern selection tasks in vegetable growing is quality products improving, obtaining high yields of environmentally safe wide assortment vegetables. To the new varieties of vegetable crops including winter white cabbage are specified new requirements such as market competitiveness, resistance to unfavorable environmental conditions, heat resistance of the varieties and F1 hybrids. The article is shown investigation results about studies of exogenous treatment by solutions on the base of physiologically active compounds of hormonal nature on the started process of stem extension stage activation and flowering of winter white cabbage plants. For the first time in the Dagestan conditions has been studied the possibility of hormonal regulation of the premature stem extension stage and flowering prevention of winter white cabbage after the initiation of natural induction. In our studies with an early planting there are not more than 20% of blooming plants, most varieties showed a high propensity to premature stem extension stage and flowering. The possibility of the hormonal exogenous regulation of the unfavorable winter white cabbage flowering has been revealed. The most pronounced effect on the transition to stem extension stage and flowering were provided by auxin nature preparations. In particular, treatment with NAS at a dose of 5 mg / l significantly reduced the number of blossom plants, krezatsin (50 mg / l) had a similar effect, but it was less pronounced. The use of cabbage in winter crops makes it possible to obtain two or three yields per year from the same area. Creation and introduction into production of promising and high-yielding varieties and hybrids will allow increasing production and reducing its cost.


Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 179
Author(s):  
Tanika Thakur ◽  
Kshitija Sinha ◽  
Tushpinder Kaur ◽  
Ritu Kapoor ◽  
Gulshan Kumar ◽  
...  

Rice is a staple food crop for almost half of the world’s population, especially in the developing countries of Asia and Africa. It is widely grown in different climatic conditions, depending on the quality of the water, soil, and genetic makeup of the rice cultivar. Many (a)biotic stresses severely curtail rice growth and development, with an eventual reduction in crop yield. However, for molecular functional analysis, the availability of an efficient genetic transformation protocol is essential. To ensure food security and safety for the continuously increasing global population, the development of climate-resilient crops is crucial. Here, in this study, the rice transformation protocol has been effectively optimized for the efficient and rapid generation of rice transgenic plants. We also highlighted the critical steps and precautionary measures to be taken while performing the rice transformation. We further assess the efficacy of this protocol by transforming rice with two different transformation constructs for generating galactinol synthase (GolS) overexpression lines and CRISPR/Cas9-mediated edited lines of lipase (Lip) encoding the OsLip1 gene. The putative transformants were subjected to molecular analysis to confirm gene integration/editing, respectively. Collectively, the easy, efficient, and rapid rice transformation protocol used in this present study can be applied as a potential tool for gene(s) function studies in rice and eventually to the rice crop improvement.


2018 ◽  
Vol 10 (4) ◽  
pp. 279-284
Author(s):  
Zh. Ivanova ◽  
K. Vasileva ◽  
N. Velkov ◽  
S. Grozeva

Abstract. Powdery mildew, caused by Podosphaera xanthii and Golovinomyces cichoracearum, is an economically important disease in melon worldwide. Genetic resistance is one of the most suitable strategies to control powdery mildew. During the last few years several races of the pathogens have been reported. The need to develop resistant varieties is a challenge for each breeding program. Leaf disc assay was used in phytopathology and breeding programs as a rapid and reliable method for evaluation of disease resistance in a large number of plant materials. The purpose of this study was to establish species and races of powdery mildew in Plovdiv region, South Central Bulgaria; to develop a suitable system of pathogen isolation and cultivation; to determine the resistance levels in different melon genotypes available in Maritsa Vegetable Crops Research Institute (MVCRI) - Plovdiv collection by the leaf disc assay. Fifty-three melon genotypes, including lines, varieties, hybrids and ten differential lines were tested. The data showed that causal agent of powdery mildew was race 1 of P. xanthii in Plovdiv region. Our experimental results indicated that for the long-term storage of powdery mildew it is preferable to keep a whole plant under in vitro conditions. This allows the preservation of powdery mildew for two months before transferring on a new tissue. Thirty-four of the tested melon genotypes reacted as immune or resistant and nineteen as susceptible. Resistant melon genotypes are a suitable source in initiating a new breeding program aimed to increase resistance to powdery mildew.


2019 ◽  
Author(s):  
Steven D. Rowland ◽  
Kristina Zumstein ◽  
Hokuto Nakayama ◽  
Zizhang Cheng ◽  
Amber M. Flores ◽  
...  

SummaryCommercial tomato (Solanum lycopersicum) is one of the most widely grown vegetable crops worldwide. Heirloom tomatoes retain extensive genetic diversity and a considerable range of fruit quality and leaf morphological traits.Here the role of leaf morphology was investigated for its impact on fruit quality. Heirloom cultivars were grown in field conditions and BRIX by Yield (BY) and other traits measured over a fourteen-week period. The complex relationships among these morphological and physiological traits were evaluated using PLS-Path Modeling, and a consensus model developed.Photosynthesis contributed strongly to vegetative biomass and sugar content of fruits but had a negative impact on yield. Conversely leaf shape, specifically rounder leaves, had a strong positive impact on both fruit sugar content and yield. Cultivars such as Stupice and Glacier, with very round leaves, had the highest performance in both fruit sugar and yield. Our model accurately predicted BY for two commercial cultivars using leaf shape data as input.This study revealed the importance of leaf shape to fruit quality in tomato, with rounder leaves having significantly improved fruit quality. This correlation was maintained across a range of diverse genetic backgrounds and shows the importance of leaf morphology in tomato crop improvement.


Sign in / Sign up

Export Citation Format

Share Document