Genotypic variation in the response of pepper to salinity

Using 102 pepper (Capsicum annuum) genotypes, a greenhouse experiment has been conducted to study genotypic variation in tolerance to 100 mM sodium chloride (NaCl) in nutrient solution. Based on the severity of leaf symptoms caused by the NaCl treatment there was a substantial genotypic variation in salt tolerance. From this screening experiment, six sensitive and six tolerant genotypes were chosen to study dry matter production and root and shoot concentrations of sodium (Na), potassium (K) and calcium (Ca) in a growth chamber experiment in a nutrient solution with and without 150 mM NaCl. The genotypes selected as sensitive were highly damaged and developed severe chlorosis and necrosis under NaCl treatment, while the genotypes selected as tolerant were slightly affected. On average, decreases in shoot dry matter production caused by NaCl were greater in the sensitive than the tolerant genotypes. Application of salt increased shoot Na concentration at greater amount in the sensitive than the tolerant genotypes. Of the tolerant genotypes, the genotype Cac (Capsicum annuum var. cerasiforme) and 1245 F1 had around 2.45% Na in shoot while the sensitive genotypes Kandil and Pazarcik contained, on average, 5.4% Na. All sensitive and tolerant genotypes exhibited more or less similar shoot concentrations of K and Ca. There was very significant and positive correlation between severity of leaf symptoms and shoot Na concentration, but no correlation could be found in the case of K or Ca concentrations with the severity of leaf symptoms. The results indicate existence of substantial genotypic variation in tolerance to NaCl stress in pepper. It seems very likely that exclusion of Na from roots into growth medium plays a critical role in expression of high Na tolerance in pepper

Indução de divisão nuclear simétrica e estruturas multinucleadas em micrósporos de berinjela (Solanum melongena L.) cultivados in vitro

Uma modificação de um protocolo utilizado para induzir embriogênese a partir de micrósporos de tabaco foi testada em berinjela (Solanum melongena L.). Em tabaco, micrósporos uninucleados são submetidos a um tratamento de estresse em meio "B" contendo manitol a 33ºC por seis dias. Os micrósporos são então transferidos para um meio AT3 contendo maltose para as fases posteriores de desenvolvimento. Neste estudo, micrósporos uninucleados e binucleados tardios do cultivar de berinjela Bambino foram pré-cultivados em meio "B" e, posteriormente, incubados a 4ºC, 25ºC e 33ºC por dois dias. Após os pré-tratamentos, as culturas de micrósporos foram transferidas para o meio AT3 contendo maltose 0,25 M e mantidas a 25ºC no escuro. A presença de divisão simétrica e estruturas multinucleadas foram verificadas com coloração DAPI do núcleo após uma e duas semanas. Foram observadas divisões simétricas dos núcleos e estruturas multinucleadas somente em micrósporos uninucleados, pré-tratados a 33ºC por dois dias. A frequência de estruturas multinucleadas foi de 19,4% sob essas condições. Nós demonstramos que a berinjela responde ao protocolo modificado de tabaco para produção de divisões simétricas e estruturas multinucleadas. Esses resultados podem ser utilizados como base para uma completa adaptação do sistema de tabaco em berinjela.A modification of a protocol used to induce tobacco microspore embryogenesis was tested in eggplant (Solanum melongena L.). In tobacco, uninucleate microspores are subjected to stress treatment by culturing in mannitol containing "B" medium at 33ºC for six days. The microspores are then transferred to maltose containing AT3 medium for further development. In the experiment presented here late uninucleate and bi-nucleate microspores of the eggplant cultivar Bambino were pre-cultured in B medium and then incubated at +4ºC, 25ºC and 33ºC, respectively, for two days. After the pre-treatments, microspore cultures were transferred to AT3 medium containing 0.25 M maltose and maintained at 25ºC in the dark. Presence of symmetrical division and multinucleate structures was checked with DAPI staining of the nucleus after one and two weeks. Symmetrical division of the nucleus and multinucleate structures were observed only in uni-nucleate microspores pre-treated at 33ºC for two days. The frequency of multinucleate structures was 19.4% under these conditions. We demonstrated that eggplant is responsive to the modified tobacco protocol in the production of symmetrically division and multinucleate structures. These results may be used as a basis for adaptation fully of the tobacco system in eggplant

Induction of symmetrical nucleus division and multi-nucleate structures in microspores of eggplant (Solanum melongena L.) cultured in vitro

A modification of a protocol used to induce tobacco microspore embryogenesis was tested in eggplant (Solanum melongena L.). In tobacco, uninucleate microspores are subjected to stress treatment by culturing in mannitol containing "B" medium at 33ºC for six days. The microspores are then transferred to maltose containing AT3 medium for further development. In the experiment presented here late uninucleate and bi-nucleate microspores of the eggplant cultivar Bambino were pre-cultured in B medium and then incubated at +4ºC, 25ºC and 33ºC, respectively, for two days. After the pre-treatments, microspore cultures were transferred to AT3 medium containing 0.25 M maltose and maintained at 25ºC in the dark. Presence of symmetrical division and multinucleate structures was checked with DAPI staining of the nucleus after one and two weeks. Symmetrical division of the nucleus and multinucleate structures were observed only in uni-nucleate microspores pre-treated at 33ºC for two days. The frequency of multinucleate structures was 19.4% under these conditions. We demonstrated that eggplant is responsive to the modified tobacco protocol in the production of symmetrically division and multinucleate structures. These results may be used as a basis for adaptation fully of the tobacco system in eggplant

Responses of Some Melon (Cucumis sp.) Genotypes to Salt Stress

WOS: 000261499500012The aim of this research is to identify differences in salt tolerance of melon genotypes and the possibility of using plant biomass values and degree of ion accumulation of leaves to determine salt tolerance. In addition, the increase in MDA amount of leaves on salt stress was evaluated. 36 different genotypes were identified according to different parameters in respect to salt tolerance and susceptibility to salinity, correlation coefficients among these characters were determined, It was observed that salt damage in melons is probably the result of toxic effects of Na+ and Cl- ions and the genotypes having low amounts of these ions are more tolerant. Midyat, Besni and Semame varieties were determinad as salt tolerant melon genotypes; Ananas and Yuva melon cultivars were most sensitive to salt stress

Screening of Turkish Melon Accessions for Resistance to ZYMV, WMV and CMV

<span style="font-family: Times New Roman; font-size: small;"> </span><p style="margin: 0in 0in 0pt; text-align: justify;" class="MsoNormal"><span style="font-family: Times New Roman;"><span lang="EN-US" style="color: #221e1f; font-size: 10pt; mso-bidi-font-family: &quot;Garamond Premier Pro&quot;;">In the Çukurova University Department of Horticulture more than 350 melon accessions were collected from different ecological parts of Turkey which is located on the secondary genetic diversification center of this crop, and their characterization studies are near completion. Furthermore, evaluation studies of these materials have started. In the present study 67 melon accessions, sampled from this germplasm, were tested for resistance to </span><span style="color: #221e1f;"><span class="A4"><span lang="EN-US" style="font-family: &quot;Times New Roman&quot;,&quot;serif&quot;; font-size: 11pt; mso-bidi-font-family: &quot;Garamond Premier Pro&quot;;">zucchini yellow mosaic virus (</span></span><span lang="EN-US" style="color: #221e1f; font-size: 10pt; mso-bidi-font-family: &quot;Garamond Premier Pro&quot;;">ZYMV), </span><span class="A4"><span lang="EN-US" style="font-family: &quot;Times New Roman&quot;,&quot;serif&quot;; font-size: 11pt; mso-bidi-font-family: &quot;Garamond Premier Pro&quot;; mso-bidi-font-style: italic;">Cucumber </span></span><span class="A4"><span lang="EN-US" style="font-family: &quot;Times New Roman&quot;,&quot;serif&quot;; font-size: 11pt; mso-bidi-font-family: &quot;Garamond Premier Pro&quot;;">mosaic virus (</span></span><span lang="EN-US" style="color: #221e1f; font-size: 10pt; mso-bidi-font-family: &quot;Garamond Premier Pro&quot;;">CMV) and </span><span class="A4"><span lang="EN-US" style="font-family: &quot;Times New Roman&quot;,&quot;serif&quot;; font-size: 11pt; mso-bidi-font-family: &quot;Garamond Premier Pro&quot;;">watermelon mosaic virus (</span></span></span><span lang="EN-US" style="color: #221e1f; font-size: 10pt; mso-bidi-font-family: &quot;Garamond Premier Pro&quot;;">WMV). After resistance tests made by mechanical inoculation, four accessions (‘CU 100’, ‘CU 287’, ‘CU 305’ and ‘CU 328’) were found resistant to ZYMV and three accessions (‘CU 305’, ‘C 264’, and ‘C 276’) to WMV. No resistant genotype was found to CMV.</span><span lang="EN-US"></span></span></p><span style="font-family: Times New Roman; font-size: small;"> </span

The effect of zinc on growth and shoot concentrations of sodium and potassium in pepper plants under salinity stress

The effect of increasing concentrations of zinc (Zn) on NaCl toxicity was studied in pepper (Capsicum annuum L. cv. Kahramanmaras-3) plants grown in a growth chamber under controlled conditions. Plants were grown in severely Zn-deficient soil with increasing Zn (0, 2, and 10 mg Zn kg-1 soil) and NaCl (0%, 0.5% and 1.5% NaCl in irrigation water) treatments. After 46 days of growth, the plants were harvested and the shoots were analyzed for dry matter production, concentrations of Zn, sodium (Na), potassium (K), and phosphorous (P), and K/Na ratios. The results showed that Zn deficiency in soil significantly reduced shoot growth, particularly under the highest salt treatment. As expected, increasing the application of NaCl reduced shoot dry matter production; however, this decrease was greater in the 2 mg Zn kg-1 soil compared to the 10 mg Zn kg-1 soil. Increases in Zn application from 2 to 10 mg kg-1 soil reduced shoot concentration of Na and elevated K concentration. Consequently, K/Na ratios of plants were highest in the highest Zn application condition. The results of the present study indicated the importance of the Zn nutritional status of plants in improving salt stress tolerance. Possibly, by affecting the structural integrity and controlling the permeability of root cell membranes, adequate Zn nutrition reduces excess uptake of Na by roots in saline conditions. Adequate Zn nutrition is, therefore, important for the maintenance of good growth and yield under saline conditions