نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار پژوهش موسسه تحقیقات خاک و آب
2 استاد گروه گیاهپزشگی دانشگاه تربیت مدرس
3 استاد گروه علوم خاک دانشگاه تربیت مدرس
4 دانشیار گروه علوم خاک پردیس کشاورزی و منابع طبیعی دانشگاه تهران
5 کارشناس بخش تحقیقات بیولوژی خاک موسسه تحقیقات خاک و آب
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Agrobacterium rhizogenes induces the formation of root hairs in dicotyledons by transferring a piece of DNA called T-DNA from its Ri plasmid into the genome of the host plant. Root hairs produced as such display two major characteristics, one being a fast rate of growth, and the other genetic stability. A very interesting characteristic of induced root hairs is their potential to synthesize growth hormones and to survive in synthetic culture media free from shoots. Such a capability has made it possible to multiply Arbescular mycorrhizal fungi, an obligate symbiotic organism on plant roots on industrial scales. Currently, simultaneous culturing of induced root hairs and surface sterilized spores of Arbescular mycorrhizal fungi is the most successful and the most economical method of producing Arbescular mycorrhizal fungi worldwide. This investigation was carried out with the objective of developing and expanding the method of production of induced root hairs as one of the two components of in situ reproduction of Arbescular mycorrhizal fungi. Induced root hairs were prepared using two strains of Agrobacterium rhizogenes, A4V and A4S on five different plant tissues, namely, carrot slices, leaves from potato and bean plants and orange trees, and the sub-cotyledon axis of chickpea seedlings. A culture of bacteria grown on YMA medium for 48 hours was used for inoculating the sub-cotyledon axis of chickpea seedlings, while a bacterial suspension with population densities of 107 cells/ml prepared in LB medium followed by transferring to MS culture was used for inoculating the other four plant tissues. Induced root hairs emerged on potato and bean leaf tissues and on the sub-cotyledon axis of chickpea seedlings. In order to prevent bacterial contaminations, the induced roots were grown in an MS medium that contained 500 mg/liter of cephotaxim. The investigation indicates that the different plant tissues show different levels of response to the inoculation with Agrobacterium rhizogenes, so that the chickpea tissue appeared to be the best while the leaves of orange tree turned out to be the least effective tissue for root hair induction.
کلیدواژهها [English]