Characterization of Solanum spp for Grafting and its Interpretation on Morphological, Production and Nutritional Quality of Fruit Under Polyhouse

Seven wild Solanum species (viz., S. torvum, S. macrocapon, S. incanum, S. aethiopicum, S. sisymbrifolium, S. viarum, and S. indicum) were grafted onto three brinjal scions (viz., Patakata, PusaShyamla, and Bhangor) for its evaluation based on compatibility ratio and further characterization of successful graft combination for morphological, yield and quality attributing characters. On persual of grafting success percentage, Patakata and PusaShyamla grafted onto S. torvum had high compatibility and success rate. The species S. torvum exhibited better adaptability to the prevailing climate which led to more success indicating their compatibility. Complete failure on grafting was noticed in the species S. aethiopicum, S. indicum, and S. sisymbrifolium. The vegetative parameters were found to be maximum from the grafting combination of Patakata onto S. torvum, wherein PusaShyamla grafted onto S. torvum and S. macrocarpon exhibited high yield attributing characters and crop duration. Given quality parameters, the maximum values were attained from the combination of PusaShyamla and Patakata onto S. torvum.

Production and characterization of inter and intraspecific hybridization eggplant

ABSTRACT The eggplant is a highly valuable horticultural crop grown all over the world and it is of substantial economic importance in Asia. However, its production is severely threatened by several soil-borne and foliar diseases, insect-pests, drought, heat, and frost damage. Therefore, efforts to transfer useful resistance genes into eggplant from their wild relatives is important. In the present study, interspecific and intraspecific hybridization was carried out, that included three cultivated genotypes of eggplant (Solanum melongena MEE, Solanum melongena MEP, Solanum melongena MEB) and one wild Solanum species (Solanum incanum INC). The F1 hybrids were made by inter and intraspecific hybridization. A total of 632 possible inter and intraspecific reciprocal crosses was performed where only three were successful. The minimum days to flowering were observed in parent MEP, and maximum plant height was measured in MEE×MEB. Maximum fruit length was observed in parent MEB. Furthermore, fruit diameter, leaf width, leaf length, and fruit yield per plant were found maximum in hybrid MEExINC. Our results suggest that these materials will be of great interest for the genetic improvement of eggplant; they may have a tremendous potential to increase tolerance to abiotic stresses, such as to drought and heat, as well as increased nutrient and herbal values. Findings of this study will be helpful for the human health, ultimately contributing to the development of a new generation of plants adapted to climate.

RESISTANCE TO LATE BLIGHT OF POTATO CLONES IN SEGREGATING HYBRID POPULATIONS

Late blight remains among the main problems of potato industry. Interspecific hybridization with the wild Solanum species is an efficient way to increase the resistance to this disease, though is accompanied with negative traits. To solve this problem, new sources of resistance, including resistant breeding clones with improved agronomic characteristics, are needed. In the present study, we investigated resistance of three hybrid populations derived from crossesbreeding of resistant original clone SW93-1015×adg with susceptible cultivars: ‘Аurora’, ‘Desirée’ and ‘Valor’. High predominance of the resistant plants was found among the hybrids (SW93-1015×adg)×Aurora and (SW93-1015×adg)בDesirée’. The numbers of resistant and susceptible plants within hybrid Valor’×(SW93-1015×adg) were almost equal. Results showed the efficiency of clone SW93-1015×adg as the late blight resistance source. Within each segregating population, the selection of resistant clones was possible. Clone SW93-1015×adg can be used in breeding programs for the hybridization with susceptible cultivars characterized by other useful characteristics.

Ethylene Differentially Modulates Hypoxia Responses and Tolerance across Solanum Species

The increasing occurrence of floods hinders agricultural crop production and threatens global food security. The majority of vegetable crops are highly sensitive to flooding and it is unclear how these plants use flooding signals to acclimate to impending oxygen deprivation (hypoxia). Previous research has shown that the early flooding signal ethylene augments hypoxia responses and improves survival in Arabidopsis. To unravel how cultivated and wild Solanum species integrate ethylene signaling to control subsequent hypoxia acclimation, we studied the transcript levels of a selection of marker genes, whose upregulation is indicative of ethylene-mediated hypoxia acclimation in Arabidopsis. Our results suggest that ethylene-mediated hypoxia acclimation is conserved in both shoots and roots of the wild Solanum species bittersweet (Solanum dulcamara) and a waterlogging-tolerant potato (Solanum tuberosum) cultivar. However, ethylene did not enhance the transcriptional hypoxia response in roots of a waterlogging-sensitive potato cultivar, suggesting that waterlogging tolerance in potato could depend on ethylene-controlled hypoxia responses in the roots. Finally, we show that ethylene rarely enhances hypoxia-adaptive genes and does not improve hypoxia survival in tomato (Solanum lycopersicum). We conclude that analyzing genes indicative of ethylene-mediated hypoxia acclimation is a promising approach to identifying key signaling cascades that confer flooding tolerance in crops.

Evaluation of Solanum species and eggplant cultivated varieties for bacterial wilt resistance

Bacterial wilt caused by Ralstonia solanacearum is one of the major diseases in Solanum species including cultivated Eggplant (Solanum melongena L.). Bacterial wilt (BW) disease management in eggplant is difficult due to high survival rate of pathogen in soil and chemical application is not eco-friendly. The best way to avoid bacterial wilt in eggplant is using disease-resistant varieties. However, only a limited number of bacterial wilt resistant varieties are available and, there is a necessity to identify and/or develop new resistant varieties. In the current study, wild Solanum species, and eggplant cultivated varieties were evaluated against Ralstonia solanacearum, and disease incidence was recorded. The cultivated varieties IIHR-108, Pusa Purple Long and Rampur Local were identified as susceptible, whereas, IIHR-7 and CARI-1 were identified as resistant to bacterial wilt. These resistant wild and cultivated varieties can be used as a root-stock in bacterialwilt disease resistant breeding programmes.

Late Blight Resistance Screening of Major Wild Swedish Solanum Species: S. dulcamara, S. nigrum, and S. physalifolium

To understand the contribution of wild Solanum species to the epidemiology of potato late blight in Sweden, we characterized the resistance of the three putative alternative hosts: S. physalifolium, S. nigrum, and S. dulcamara to Phytophthora infestans, the causal agent of late blight. The pathogen sporulated in all 10 investigated S. physalifolium genotypes, suggesting susceptibility (S phenotype). Field-grown S. physalifolium was naturally infected but could regrow, though highly infected genotypes were smaller at the end of the season. In 75 S. nigrum genotypes, there were no symptoms (R phenotype) or a lesion restricted to the point of inoculation (RN phenotype), indicating resistance. In 164 S. dulcamara genotypes, most resistance variability was found within sibling groups. In addition to the three resistance phenotypes (R, RN, and S), in S. dulcamara a fourth new resistance phenotype (SL) was identified with lesions larger than the point of inoculation but without visible sporulation of the pathogen. Quantitative PCR confirmed P. infestans growth difference in RN, SL, and S phenotypes. Thus, in Sweden S. physalifolium is susceptible and could be a player in epidemiology. A limited role of S. dulcamara leaves in the epidemiology of late blight was suggested, since no major symptoms have been found in the field.