Search

Salt stress is one of several major abiotic stresses that affect plant growth and development, and there are many evidences that silicon can ameliorate the injuries caused by high salinity. This study presents the results of an assay concerning: (1) the effect of in vitro NaClinduced salt stress in cape gooseberry plants and (2) the possible mitigating effect of silicon in saline conditions. For that, nodal segments were inoculated in Murashige and Skoog (MS) medium under salinity (0.5 and 1.0% NaCl) with different silicic acid concentrations (0, 0.5 and 1.0g L-1). Phytotechnical characteristics, photosynthetic pigments content, and leaf anatomy were evaluated after 30 days. Shoot length, root length, number of leaves and buds, fresh and dry weight, pigment content, stomatal density and leaf blade thickness were drastically reduced by increased salt level. The supply of silicon (1.0g L-1) has successfully mitigated the effect of salinity at 0.5% NaCl for chlorophyll, carotenoids, stomatal density and leaf blade thickness. When salt stress was about 1.0%, Si was not effective anymore. In conclusion, we affirmed that, in in vitro conditions, salt stress is harmful for cape gooseberry plants and the addition of silicon showed effective in mitigating the saline effects of some features. [ABSTRACT FROM AUTHOR]

The macaw is a palm oleaginous that it is highly productive and in which their oil can be used to produce biofuels.This study aimed to evaluate the influence of concentrations of minerals of the culture medium MS and coconut water germination in vitro of zygotic embryos of macaw and initial growth of seedlings. The embryos were inoculated in test tubes containing 15mL of culture medium MS in concentrations of 50 and 100% of minerals, plus coconut water (0, 50, 100 and 150mL L-1). The cultures were kept in room for growth with irradiance around 42W m-2, at 25±2°C and photoperiod of 16 hours. Higher percentage of germination of embryos of 'macaúba' was obtained at 60 days in MS medium in the original concentration of salts. The growth and conversion to viable seedlings or normal, which can be acclimatized, require half the concentration of salts of MS medium supplemented with 50mL L-1 coconut water. [ABSTRACT FROM AUTHOR]

Effective protocols for in vitro rooting for woody fruit trees are still a challenge for in vitro seedling production, especially when there is a need to insert new cultivars or rootstocks. These protocols are essential to accelerate studies in plant breeding programs and for seedling distribution. This study evaluated the use of 6-Benzylaminopurine (IBA) in in vitro rooting of Pyrus comunnis rootstocks, clones 'OHxF87' and Pyrodwarf. Explant exposure times (0, 24, 48, 72, and 96 hours) to 20 mg L-1 IBA were tested for in vitro rooting. The exposure to IBA resulted in rooting rates above 80%, surpassing some results reported in the literature. The 24-hour treatment provided 81,81% survival, leading to an average growth of five roots with 19 mm length, for 'OHxF87' rootstock. The same exposure time resulted in the highest survival rate (75%) and the highest mean root number, seven roots per plant with 10 mm length, for 'PDW' rootstock. Root formation did not occur in the absence of synthetic auxin. Therefore, it can be concluded that a 24-hour exposure at 20 mg L-1 IBA was sufficient to promote in vitro rooting in 'OHxF87' and Pyrodwarf rootstocks'. [ABSTRACT FROM AUTHOR]

The production of the macadamia walnut is measured in "nut in peel" (peel and almond). The cultivar that have higher caliber has greater commercial value. The objective of the present research was to analysis of fruits and nuts of 22 cultivars of macadamia walnut. The cultivars used were: 'África', 'Beaumont' (695), 'Cannon', 'C160', 'Doroti', 'Edson', 'Flor Rosa', 'HAES 722', 'HAES 814', 'HAES 816', 'HAES 842', 'HAES 849', 'IAC Campinas-B', 'IAC 9-20', 'IAC 9-20X', 'IAC 4-12B', 'Kau' ('HAES 344'), 'Keauhou' ('HAES 246'), 'Keaumi' ('IAC 4-20'), 'Mauka' ('HAES 741'), 'Pahala' ('HAES 788') and '791 Fuji'. It was determined the dimensions (length and diameter) and the fresh weight of the carpelo, peel and almond, besides the fresh weight of the "nut in peel" (peel and almond), besides TR (relationship among the weight of the nut in peel and the weight of the rescued almonds). The cultivars presented differences as the dimensions of the fruits. The cultivar 'Edson' presented fruits and nuts with larger dimensions and weight. The cultivars 'Pahala', 'Beaumont', 'IAC 9-20X' and 'Keaumi' presented TR lower than 30%. [ABSTRACT FROM AUTHOR]

The use of micropropagated orchid seedlings is very widespread in floristic broadcast market, since the reproductive cycle of the same is significantly reduced. Therefore, this study aimed to evaluate the influence of environments for growing concentrations of BAP (benzylaminopurine) and NAA (naphthalene acetic acid) in relation to the budding and growth of seedlings of native orchids (Laelia crispata), and hybrid [(Laeliacattleya Culminant "Tuilerie" x Laeliacattleya Sons Atout Rotunda) x Bassolaelia Cattleya Startifire Moon Beach] to reduce production costs and improved quality of seedlings. Seedlings from seeds germinated in vitro with approximately 0.6cm long and were inoculated in test tubes containing 15mL of culture medium MS plus BAP (0, 2.0 and 4.0mg L-1), NAA (0, 1.0 and 2.0mg L-1) and the growing environment (dark and growth room with artificial light) in all possible combinations. At the end of 150 days, the number of shoots, leaves and internodes and the average length of shoots were evaluated. The number of shoots and internodes in orchid seedlings (native and hybrid) was significantly higher in the environment in the absence of light independent of the concentration of plant growth regulator used. The native species had higher number of internodes with the use of 2.0mgL-1 NAA in the absence of BAP, and the hybrid orchid showed a higher number of inmates with the use of 2.0mgL-1 NAA. [ABSTRACT FROM AUTHOR]