نوع مقاله : گزارش کوتاه
نویسندگان
1 عضو هیئت علمی موسسه تحقیقات چغندرقند، کرج، ایران
2 عضو هیئت علمی مؤسسه تحقیقات چغندرقند، کرج
3 عضو هیئت علمی مرکز تحقیقات کشاورزی، صفی آباد
چکیده
عنوان مقاله [English]
نویسندگان [English]
Commonly sugar beet roots are damaged during and after harvesting causing considerable amount of yield losses. In addition the damaged roots cause an increase in respiration rate, growth of fungal pathogens, root rots and sucrose losses (accumulation of invert sugars) in stored roots. Furthermore at harvest a considerable amount of soil remains on the roots and is delivered to the factory causing an increase in the transportation costs, soil erosion, spreading soil -borne diseases (nematode and rhizomania), an increase in the amount of water used and costs of washing process in the factory. To reduce these losses in addition to the utilization of improved methods of cultivation and mechanisation, the varieties which are less damaged and transfer fewer soil with their roots during and after harvest should be used. Generally the root shape of commercial sugar beet varieties is conical and two grooves of little depth are noticed on the roots. Since the root ends are fragile, during the stages of harvesting till to the processing stage they are damaged and also the adhered soil to the root grooves is delivered to the factory. By genetically modifying the traditional conical morphology of the sugar beet to a globe-shaped or oval root with a smooth skin the problem can be solved. The genetic variation for root shape within the gene pools of sugar beet is limited. However globe - shaped and oval-shaped roots could be found in fodder beet and in red beets lines. With this objective. since 1997, in a breeding program at the sugar beet seed institute (SBSI) we started to transfer globe -shaped and oval-shaped roots characters from reel beets and fodder beets to the conical-shaped sugar beets. After evaluation of red beets and fodder beets landraces the desired characters have been identified and were transferred to the sugar beets by crossing. subsequent back-crossing and recurrent selection. At the moment, new sugar beet lines with globe-shaped mid a smooth skin characters have been produced. Interestingly new and improved lines have the potential to produce high root yield but the research is carrying on to increase quality characters of these lines.
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