Effect of concentrates level on digestibility, ruminal fermentation, and bacterial community in growing camels.

Understanding the rumen microbiota of camels under different feeding conditions is necessary to optimize rumen fermentation and productivity. This study aims to investigate the effects of different concentrate supplement levels on digestion, rumen fermentation and bacteria in growing camels. Fifteen growing camels were divided into three groups and were fed alfalfa hay in addition to one of the three concentrate supplement levels based on body weight (BW): low (0.7%), medium (1%), and high (1.3%). Increasing the concentrate supplement level in the diet increased total dry matter intake but had no effect on nutrients digestibility, except for crude protein digestibility, which was enhanced with the high concentrate level. Growing camels at low-level had considerably higher rumen pH than those fed medium or high levels. Increasing the supplement level also increased rumen propionic acid but decreased acetic acid concentration. Principal coordinate analysis showed that concentrate levels clearly separated the ruminal bacterial communities where Bacteroidetes and Firmicutes were the dominant phyla and Prevotella, Ruminococcus, Butyrivibrio, RC9_gut_group, and Fibrobacteres were the dominant bacterial genera. This study expands our knowledge regarding the rumen microbiota of growing camels under different concentrate levels and reveals that medium concentrate levels could be appropriate for growing camels.

High-frequency direct somatic embryogenesis and plantlet regeneration from date palm immature inflorescences using picloram.

BACKGROUND: Date palm (Phoenix dactylifera L.) is a traditional crop in arid and semi-arid areas. Its vegetative propagation can be achieved by offshoots, but possible number of offshoots in mother palm trees is limited. Micropropagation is a highly recommended strategy for obtaining date palm elite cultivars using shoot tip and immature inflorescences. In this study, micropropagation procedure using inflorescence explants of Medjool cv. is described. For culture initiation, explants from different spathe lengths were cultivated on Murashige and Skoog medium (MS) supplemented with picloram at 1.0 and 2.0 mg/l combined with 2iP at 0.5 mg/l alone and with both 2iP and BA at 0.25 mg/l for 24 weeks. The obtained direct globular embryos were transferred to maturation media with 0.1 mg/l picloram alone or combined with both 2iP and ABA separately and together for further development. Additionally, multiplication and rooting media were optimized by different cytokinins and auxins for high frequency of plantlet production. Acclimatization of in vitro plantlets was also investigated. RESULTS: The highest percentage of globular embryo formation was noticed with explants isolated from spathe lengths ranging from 10 to 15 cm. Addition of BA to initiation media with picloram encouraged a significant effect on embryonic culture formation percentage. Incorporation of ABA and 2iP to maturation medium was an effective factor for individual or multiple embryo emergence. Acclimatization of in vitro plantlets having 3-4 roots was successfully accomplished. Irrigation with the full strength solution (MS) encouraged the highest growth vigor degree, leaf number/plant, leaf width, root number, and root thickness degree of ex vitro plants. CONCLUSION: This research provides an advanced regeneration system for large-scale production of date palm from immature inflorescences of Medjool cv. It opens up the prospects of using picloram with different growth regulators for rapid micropropagation of date palm.

Thidiazuron-induced direct organogenesis from immature inflorescence of three date palm cultivars.

BACKGROUND: Inflorescence explants of date palm proved to be a promising tool for micropropagation of elite cultivars or rare males and females as organogenesis and somatic embryogenesis could be achieved. These plant materials are abundantly available every year and can be used as cheap and potent explants. Nevertheless, many difficulties could be faced in this protocol according to selection of the spathe size and age, media components, growth regulators, etc. The aim of this study was to determine the influence of various cytokinins on direct organs induction of three date palm cultivars (Selmi, Barhee, and Medjool) from immature inflorescence. An additional objective of this study was to investigate the effect of cytokinins and auxins on growth and development of Medjool cultivar. RESULTS: Various combinations of cytokinins were investigated on three date palm inflorescences as N6-(2-isopentenyl) adenine (2iP), kinetin, benzyleadenine (BA), and thidiazuron (N-phenyl-N'-1,2,3-thidiazol-5-yl urea) (TDZ). TDZ alone or in combination with BA proved to be superior for direct organogenesis in all three cultivars so that another combination of TDZ with BA was conducted. Results showed that moderate concentration of BA, with TDZ, gave superior response. Medjool cultivar response surpassed other two cultivars that made the possibility to conduct some growth regulators treatments on its multiplication and regeneration. TDZ at 0.5 + BA at 1.0 mg/l without activated charcoal seemed to enhance multiplication rate. Medium containing 0.5 mg/l of both naphthaleneacetic acid and indole butyric acid in addition to 1.0 mg/l indole acetic acid appeared to be more suitable for rooting stage of Medjool shootlets. CONCLUSION: In this study, we created an innovation sequence of growth regulators included in nutrient media for date palm direct organogenesis from inflorescence. Organogenesis has been accelerated from immature inflorescence explants and developed to healthy plantlets which acclimatized in greenhouse.

Microprojectile Bombardment Transformation of Date Palm Using the Insecticidal Cholesterol Oxidase (ChoA) Gene.

The overall objective of this work is to optimize the transformation system for date palm as a first step toward production of date palm clones resistant to noxious pests. A construct harboring the cholesterol oxidase (ChoA) gene, which renders plant resistance against insect attack, is introduced into embryogenic date palm callus using the PDS-1000/He particle bombardment system. The process involves the establishment of embryogenic callus cultures as well as immature embryo-derived microcalli that are used as target tissues for shooting and optimization of transformation conditions. This chapter in addition explains molecular and histochemical assays conducted to confirm gene integration and expression.