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Plant Breeding & Genetics
Highlights
The United Arab Emirates (UAE) University is organizing "The Third International Conference on Date Palm", Time: 13 - 15 November 2005. Venue: Emirates Palace Hotel, Abu Dhabi, UAE.
Contacts:
  1. Prof. Abdelwahab Zaid, (ph.: 971 3 783 2334; fax: 971 3 783 2472; E-mail: zaid@uaeu.ac.ae
  2. Prof. Vincent Hegarty; (ph.: 971 3 763 5647; fax: 971 3 763 2384; E-mail: vincent.hegarty@uaeu.ac.ae

Fruiting in micropropagated date palm tree, variety ‘Deglect Noor’ -TC project RAF/5/035
FOCUS on: Producing date palm trees with improved fruit yield, short height, and resistance to Bayoud disease.
Date palm is one of the most important fruit trees the Middle East and in the Saharan and Sub-Saharan regions of Africa. In some areas, this is the only tree which provides food, shelter and fuel to the communities. Dates are not only a staple food but are also an important export cash crop. Conventionally, date palms are propagated from young shoots which appear as suckers at the base of the tree. Thus, it is possible to multiply well known
good quality females and have the desired ratio of male to female trees in a plantation. However, the outbreak of Bayoud disease in an epidemic form in the Sahara region has made conventional methods of tree propagation unreliable and undesirable. The disease is caused by the soil-borne fungus, Fusarium oxysporum sp. albedinis. The pathogen enters the plant via roots, travels through the xylem, and causes white leaves (hence the name 'Bayoud'). In-vitro propagation of selected date palms offers a practical solution for obtaining high quality, disease free propagules in large numbers. Since the life span of the date palm is long, and it takes up to seven years before a plant fruits for the first time from seed propagation, the conventional methods of propagation are too slow and inefficient, and the genotypes produced are completely different from the parental variety. To overcome these problems, the existing varieties which have good quality but are susceptible to Bayoud disease can be upgraded through induced mutations. This can now be accomplished by in-vitro irradiation of tissue cultured material, such as explants, somatic embryos and callus cultures. In addition to susceptibility to Bayoud disease, some of the cultivars with good fruit quality do not have adequate fruit yield and are too tall in growth habit. There is thus a need to improve yield by producing short height genotypes, as has been achieved in some temperate fruit trees such as apples. Short height also allows a higher density of planting per unit area and would thus lead to an increased yield. The production of disease-resistant mutants of the existing cultivars with high yield and quality will restrict the spread of Bayoud and other diseases through the spread of healthy and uninfected material. Both domestic availability and export potential of dates will be enhanced.
Since 1997, the Agency has been assisting the three Maghreb Countries (Morocco, Algeria, Tunisia) in developing disease-free varieties with higher yield, better quality, and other desirable traits (RAF5035, RAF5049). Good results in the isolation of Bayoud toxin and in vitro grown date palm plantlets were obtained. These results now lead to the (1) assessment in the field of the performance of the developed improved mutants, particularly against Bayoud toxin, (2) screening of mutants and of the genetic variability, and (3) streamlining the legal and technical procedures for the transfer of biological substances and in vitro genetic materials.

Establishment of First IAEA Collaborating Centre in Zhejiang University, China, November 2004: It will jointly work with Plant Breeding and Genetics Section for 3 3 years on Mutant Germplasm Enhancement and Exploration in Plants. The innovative projects included are: Induced Mutants for Rice Functional Genomic Studies; Targeted Mutagensis for the Selection of Important Quality and Agronomic Traits; Evaluation of the Effects of Gamma Rays on Rice DNA. These projects will further enhance the capacity of mutation techniques for plant improvement in the genomics era. pdf.

New chrysanthemum mutants lines.
Project: THA/5/045. Counterpart: Prof. Siranut Lamseejan, Thailand.



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Chrysanthemum Purple color of the original variety 'Reagan Dark Splendid'


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Selected variants of chrysanthemum from M1V3 plants irradiated with acute gamma rays of 30 Gy


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Selected variants from M1V3 chrysanthemum plants irradiated with chronic gamma rays of 112 Gy


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Selected variants from M1V3 chrysanthemum plants irradiated with chronic gamma rays of 140 Gy

PBG Images Gallery

The FAO/IAEA Mutant Varieties Database (MVD) is now available through Internet: http://www-mvd.iaea.org/

Cost Reduction in banana micropropagation by using skylights as a source of natural light.
Day light instead of artificial light was exploited for the in vitro culture of banana. Tubular skylights diverted natural light into an interior enclosed room and could sufficiently illuminate an area of 3 to 5 m2. The cost of a tubular skylight is ca. US $ 600. The maintenance-free system allowed only a minimum of heat transfer and no cooling was necessary. The culture room required no electricity supply and under our conditions savings on costs for electricity of US$ 6 per m2 per week were achieved as compared to a standard growth room equipped with artificial lighting and controlled photoperiod and temperature regimes. 
Under natural light conditions, micropropagated plantlets were well developed at mean photosynthetic photon flux densities (PPFD) of 5 to 13 mmol m-2 s-1 and photoperiods of 9 to 14 hours. Micropropagation rates were either the same or significantly higher than under artificial lighting. Single shoots on rooting medium showed some symptoms of etiolation yet acclimatisation rates averaged 95 %.

Current Events
To overcome completely the problem of chimerism after mutagenic treatment embryogenic cell suspensions (ECS) are highly suitable material for in vitro mutagenesis. Nevertheless we have shown that old embryogenic cell suspension cultures become polyploid or aneuploid after several subcultures. The use of flow cytometry has enabled us to eliminate genetically unstable clones in mutation induction experiments.
Eight banana plants from irradiated cultures of 'Grande Naine' were selected for tolerance to Juglone, the main toxin produced by the fungus Mycosphaerella fijiensis. This fungus causes Black Sigatoka disease, one of the most devastating diseases of banana. If the resistance of these plants will be confirmed through inoculation with the fungus and field evaluation under high disease pressure, a tremendous impact on environmentally save banana production and food security can be expected.



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