IMPROVING PRODUCTION AND CHARACTERS OF POTATO MICROTUBERS AND MINITUBERS

Abstract

This investigation was carried out during the seasons 2012 and 2013 on potato cv. Diamant at the Tissue Culture Laboratory and the greenhouse of Potato and Vegetatively Propagated Vegetables Department, Horticulture Research Institute, Dokki, Giza, Egypt. The present study aimed to study the effect of the in vitro application of chitosan, calcium chloride and the concentration of ammonium nitrate and potassium nitrate on potato tuberization. In addition, to study the effect of foliar application of chitosan, chelated calcium and potassium silicate on growth and yield of the minituber ex vitro. Results revolved that 500 mg/l chitosan gave the highest values of number of shoots and node/plantlets, number of microtuber, fresh and dry weight of shoots and microtubers fresh weight after 8 weeks from culture in vitro. Furthermore, ex vitro spraying with 500 mg/l chitosan or the mixture of 350 mg/l chelated calcium + 400 mg/l potassium silicate produced the highest values of plant length, leaves number/plant, fresh and dry weight of leaves on 75 days after planting. As well as, minituber characteristics (number of minituber /plant, minituber fresh and dry weight/plant, average minituber weight and weight of minituber /plant according to its size) after 100 days from planting recorded the highest significant values with foliar application of 500 mg/l chitosan or the mixture of 350 mg/l chelated calcium + 400 mg/l potassium silicate. It could be recommended that adding chitosan at 500 mg/l to in vitro microtuber production medium (MS + 8 mg/l BA + 80 g/l sucrose) was preferable to produce microtubers. Also, the ex vitro spraying of 500 mg/l chitosan or the mixture of 350 mg/l chelated calcium plus 400 mg/l potassium silicate could be useful for minituber production and enhancing its yield characteristics.