In Vitro Rooting of Dendrobium nobile Orchid: Multiple Responses to Auxin Combinations

Orchids are the most adorable in flowering plants, cultivated as the cut flower and potted plants throughout the world at different occasions. For their commercial exploitation and conservation of endangered species, micropropagation has been extensively practiced, which may be affected by several factors at each step. In vitro rooting is the most important stage that may ultimately be responsible for successful transplantation of the plantlets. Auxins play a vital role for in vitro rooting. In present study NAA and IBA treatments to in vitro developed microshoots produced multiple responses. Findings show that NAA concentrations alone were better and vigorous than IBA alone in terms of number, length and root thickness. Increasing the NAA concentration from 0.1 to 3.0 mg l-1 proved progressive. The highest significant value in root development was obtained with NAA at 3.0 mg l-1. In case of IBA alone, the root number was increased by increasing its concentration up to 1.0 mg l-1 but, root number decreased when the concentration of IBA was increased to 3. 0 mg l-1. However, the combined effect of both the PGRs over root formation indicated a considerable decline in root formation as well as callus formation at microshoot bases

Phenotypic Reversion of Somaclonal Variants Derived from Inflorescence of Date Palm (Phoenix dactylifera L.) in the Open Field Trials

The likelihood and degree of the reversion of somaclonal variations have not been reported for tissue-cultured date palm (Phoenix dactylifera) plants derived from immature inflorescences. In this study, three to four years old field grown tissue cultured date palm plants of cvs. Kashuwari and Gulistan derived from in vitro subculture 1-10 (block I) and 11-25 (block II) in multiplication stage were screened for type and nature of phenotypic abnormalities. Six phenotypic abnormalities were detected: 1) dwarfism, 2) excessive vegetative growth, 3) production of deformed offshoots and twisted inflorescence, 4) abnormal frond growth, 5) low levels of fruit setting and 6) inflorescence absent. Among the six different variant phenotypes, complete reversion of phenotypic abnormalities for the phenotypes of inflorescence absent, low level of fruit setting, production of deformed offshoots, and abnormal frond growth were observed in open field trial plants during the three years' study period. An overall percentage of all the variations was higher (64.19%) in block II during the first season as compared to block I (2.42%). This study provides a good indicator for the date palm tissue culture industry where in vitro cultures with subculture number <11 cycles in multiplication stage are needed to obtain higher percentage of true-to-type regenerants. © 2019, Researchers Links Ltd

Influence of pollination in liquid suspension on the date palm (Phoenix dactylifera L.) Mejhoul cultivar in the Mexicali valley, Mexico

The pollination process is one of the most important contributors to a successful date production since the yield and quality of the fruit depends on its correct successful. Liquid pollination in the date palm production is a recently used technique that seeks to obtain acceptable fruit set percentages (FSP) with lower pollen consumption. In this study, during the 2021 and 2022 growing seasons, the effect of pollination with pollen grains in liquid suspension on the FSP in the date palm cultivar ‘Mejhoul’ was evaluated in the Mexicali Valley, Mexico. The applications were in various proportions of pollen in liquid suspension (1, 2, 3 and 4 g/L), with approximately 40 mL on each inflorescence. The results revealed that the best treatment was 4 g/L with an average FSP of 67.89 and 68.69% for the years 2021 and 2022 respectively, while the control treatment obtained 54.94 and 57.75%, for the same years. Likewise, this method did not affect the physical and chemical properties and yields. Finally, this study suggests that in addition to consuming a smaller amount of pollen, this method has better pollination efficiency