Abstract
The luffa (Luffa cylindrica ROEMER.) is a wellknown sponge gourd grown in oriental regions.The young fruits pickled are eaten rarely for food and the dried pulp fibre of matured fruits is widely used for industriatl materials. In 1949 new tetraploid plants were created by colchicine treatment and then triploid ones were obtained by crossing between this induced tetraploid and the original diploid. Tetraploid luffa has merits of distinctly thicker lea.ves and stems, Iarger flowers and seeds, and, especially, strbnger pulp fibre of matured fruits than the common diploid. Regard to purity of the strain, however, the tetraploid is much inferior to diploid due to, extreme segregation of genetic characters among individual plants. And a most of them are endowed with too late rTiaturing habit and much lowered seed productability to thrive in our mild temperate regions. Triploid plants bear generally srnaller fruits and have a smail amount of fertile seeds which are ascertained afterwards to be "tetraploid" throug'h progeny testixig of' the next year. At any rate, we may be able toget, in future, the earliest useful tetraploid strain selected which will have larger flowers and stronger pulp fibre than the common luffa ones
