Callus induction of F. moluccana (sengon) was still an obstacle to indirect organogenesis regeneration. The purpose of the study was to determine the callus induction formation from root fragments of F. moluccana plantlets. Primary explants (fragments of roots) were cultivated on MS induction basal media and three concentration combination of PGRs (BAP and NAA): 0.5 ml/l BAP; 0,1 ml/l NAA (single PGR); and combination of 0.5 ml/l BAP + 0.1 ml/l NAA (double PGR). When roots were used as explants, high formation rates of callus (more than 70%) were obtained. Highest formation rates of callus were in NAA added at all clones (12 clones), then BAP added (7 clones) and BAP + NAA added (5 clones). The results indicated that BAP and NAA concentrations used in the media were influence the producing callus and affect the amount of callus produced from roots of sengon. The addition of NAA also gives higher callus proliferation results than the addition of BAP or the addition of a combination of the two hormones. The results indicated that BAP and NAA concentrations used in the media were influence the producing callus and affect the amount of callus produced from roots of sengon.

Lack of water and salinity are common problems in many parts of the world. Therefore, some types of cacti can represent as promising crops. Therefore, the ability of cactus species to survive and adapt under natural stress conditions should be evaluated. In this study, it was aimed to evaluate the effect of salt stress on germination and emergence of pitaya seeds obtained from different fruit flesh colors, priming with plant growth regulators, namely salicylic acid (SA), oxalic acid (OA) and mepiquat chloride (MC). The experiment had a completely randomized design with a 2×4×3 factorial scheme corresponding to two pitaya cultivars (white and red fleshed), four NaCl concentrations (0, 2500, 5000 and 10000 ppm), and three PGRs (150 ppm/MC, SA, OC). The following variables were analyzed; germination percentage, mean germination time (MGT), germination stress tolerance ındex (GSTI), shoot length, seedling fresh weight and seedling dry weight ratio. According to the results, it was determined that the growing environment of the seed was important in salt stress resistance, while seeds matured in the environment with red fruit flesh were more tolerant to salt stress than white. Although Pitaya species are relatively salt tolerant, growth (about 30%) was significantly reduced above 2500 ppm and germination (about 45%) above 5000 ppm. MC was found promising as a priming agent in seeds obtained from fruits with white fruit flesh, and OA was found promising as a priming agent in seeds obtained from fruits with red fruit flesh in reducing NaCl-induced stress. Germination percentage stood out as the most important trait determining seed quality and was found to have positive effects on germination stress tolerance index (r: 0.63), seedling length (r: 0.74) and fresh seedling weight (r: 0.56). It is thought that the results obtained may contribute to pitaya cultivation and breeding.

Peatlands in Indonesia are one of the world's largest carbon sinks, helping to regulate greenhouse gas emissions and global climate change. Lophostemon suaveolens is a plant found in Papua's endemic peat ecosystem that grows well in wet areas with low fertility. It is geographically dispersed and has the potential for peatland re-habilitation. We present an efficient and reproducible protocol for in vitro multiplication of plantlets using nodal segments and shoot apices collected from plantlets. The Murashige and Skoog (MS) medium was sup-plemented with single and double kinds of PGRs (BAP and NAA). The concentration used in this study is based on the best findings of earlier preliminary research on single PGR treatment (0.5 ml/l BAP and 0.1 ml/l NAA) for the initiation stage. After 3 months of in vitro axillary shoot initiation, elongated shoots from plant-lets were separated from the clumps and multiplied. Until 6 months incubation, the potential multiplication of axillary shoots was determined by counting the number of nodule multiplication coefficients (NMC), shoot length, root length, and number of leaves (6 successive subculture). The highest average per plantlet of NMC (8.4 0.13) was observed in MS medium with a combination of 0.5 ml/l BAP and 0.1 ml/l NAA (double PGRs), with the longest shoots (5.91 0.17 cm), the longest root length (8.83 0.69 cm), and the most leaves (32 0.69). They were cultured in a pH 5 environment with a light photoperiod (40 mol/m2/s intensity) for 16 hours. When BAP and NAA were used together after acclimatization, seedling survival was highest. This is the first report of L. suaveolens in vitro multiplication, and the protocol could be used to propagate this peatland species on a large scale.

Plant hormones regulate the adaptive responses to various biotic and abiotic stress factors. Applied exogenously they trigger the natural plant defense mechanisms, a feature that could be implemented in strategies for supporting crop resilience. The potential of exogenous cytokinin-like acting compound (kinetin), the auxin analogue 1-naphtyl acetic acid (NAA), abscisic acid (ABA) and the ethylene-precursor 1-aminocyclopropane-1-carboxylic acid (ACC) to mitigate dehydration was tested on Lactuca sativa (lettuce) grown on 12% polyethylene glycol (PEG). Priming with different blends containing these plant growth regulators applied in bioequivalent concentrations was evaluated through biometric measurements and biochemical analyses. The combined treatment with the four plant hormones exhibited the best dehydration protective effect. The antioxidative enzyme profiling of the PGR-primed individuals revealed increased SOD, catalase and peroxidase activity in the leaves. Immunodetection of higher levels of the rate-limiting enzyme for proline biosynthesis (delta-pyroline-5-carboxylate synthase) in the primed plants coincided with a significantly higher content of the amino acid measured in the leaves. These plants also accumulated particular dehydrin types, which may have contributed to the observed stress-relieving effect. The four-component hormonal mix applied by spraying or through the roots exerted similar stress-mitigating properties on soil-grown lettuce subjected to moderate drought.