Capsicum sp. Has been reported as a salt-sensitive crop. Therefore, using salt-tolerant varieties will be a wise solution for maintaining crop production in coastal areas. Source of saline-tolerance controlling genes are needed to develop saline-tolerant genotypes. The objective of this study was to evaluate the tolerance of cayenne accessions to salinity stress during the vegetative phase based on the leaf damage symptoms. The experiment was carried out using a hydroponic technique with a solution of macro and micronutrients AB mix supplemented by 6000 ppm NaCl. A total of 20 genotypes of cayenne pepper were evaluated in a completely randomized design with three replications. Each experimental unit consisted of two plants grown in polybags with sand media. To determine the tolerance level of plants to salinity stress, the tolerance index (TI) was calculated based on the score of leaf symptoms. The results showed that genotypes A21 and A32 exhibited better vegetative growth performance in leaf greenness, number of leaves, and stem diameter compared to other genotypes. There was no saline-tolerant genotype found. All genotypes showed abnormal symptoms on the leaves. However, the sensitivity index indicated that genotypes A21 and A32 were classified as moderately tolerant with the mildest symptoms.

Population diversity is necessary in selecting salinity tolerant plants. The objective of the study was to evaluate the tolerance of chili pepper (Capsicum sp.) to salinity stress. The evaluation was carried out artificially in a greenhouse. Twenty-four accessions of chili were grown on hydroponic media with stress treatment of 3000 ppm and 6000 ppm NaCl. As a comparison, the control was planted without NaCl. Nutrients were given from the AB mix nutrient solution containing macro and micronutrients. The study used a completely randomized design with 3 replications. To evaluate the ability of the genotype to adapt to NaCl stress, the difference between control and observations at 6000 ppm NaCl stress was calculated. The results showed that the growth of chili pepper genotypes under NaCl stress varied widely. There was an interaction between the genotype and the stress level of NaCl on leaf greenness and the number of stomata. In general, the stress of 3000 ppm NaCl significantly reduced chili performance starting from 6 weeks after transplanting. The stress of 6000 ppm NaCl caused some sensitive plants to die at 8 weeks after transplanting. The tolerant genotypes at 6000 ppm NaCl stress were A10, A21, and A33.

This research was aimed to identifying the P5CS gene involved in the drought stress mechanism in upland rice lines which is candidate as new genetic resource for breeding programs. The plant material consisted of 19 breed lines: Salumpikit and IR20 varieties, drought-tolerant and sensitive, respectively. The experiment consisted of 4 stages, including the evaluation of drought stress with 20% PEG 6000 (-0.58 MPa) in the germination and nursery phases, the vegetative phase, and the expression analysis of the P5CS gene. The results showed that the PEG inhibited the growth of roots, shoots, and the ratio of roots to shoot in the germination and nursery phases of all the tested lines, while the Salumpikit and IR20 varieties were confirmed as drought resistant and sensitive, respectively. The proline content under drought stress was significantly different in the lines tested, while Salumpikit and IR20 were confirmed to have high and low proline content, respectively. The proline content in several lines, such as G4, G6, G8, G10, G12, G13, G14, G15, and G17, exceeded the content in the Salumpikit variety. The P5CS gene was amplified in PCR analysis and expressed in the consistency of proline. It was found that the lines of G4, G6, G8, G13, and G17 showed tolerance to drought stress, had high STI values, and showed recovery ability and proline content. These lines have the potential to be released as candidates for new varieties. In addition, these lines have great potential as a new genetic source for upland rice breeding programs.