Abstract
Autotetraploid 'Sawonppong 26'was induced by dropping clochicine solution in growing point of Keomseolppong which is of high rootability and some agronomic charactelistics are as follows. Sawonppong 26 is a tetraploid of Keomseolppong with 56 of the chromosome number. Its fertlization percent was 59.4% and the germination percent of sank seed was normal. Sugar degree of mulberry fruit was 13.3% and total acidity was 0.69%. Single fruit weight of Sawonppong 26 was increased by 79%, as compared to that of Keomseolppong. Even though percent of survival of hard wood cutting was 94%, number of rootings was less and diameter of root was slender, it is expectedly a promising variety to be used for a breeding parent from the aspect of rootability.