SEX DETERMINATION of Carica papaya L. VARIETIES AT SEEDLING-JUVENILE STAGE USING MORPHO-ANATOMICAL CHARACTERS
MERCY GOSPEL AJURU *
Department of Applied and Environmental Biology, Rivers State University of Science and Technology, Nkpolu-Oroworukwo, P.M.B. 5080, Rivers State, Nigeria
*Author to whom correspondence should be addressed.
Abstract
Study aimed at determining the sex types of two varieties of Carica papaya (Orange-red and yellow) at seedling stage was conducted using morpho-anatomical characters. Morphological studies showed that at seedling stage, the female plant has broader and larger stem, larger leaf size, and grows faster and taller than the male plant. Anatomical studies of the leaf of the orange-red variety showed the male plant having 16 vascular bundles, female, 20; male with hollow pith region, and less druse crystals as compared to the female plant with parenchyma- filled pith and more druses. The petiole of the male plant possess 33 vascular bundles, female, 30; both having hollow pith which was also observed in both sex types of the yellow varieties, but the leaf of the male plant had 13 vascular bundles, female, 19; and a pith filled with parenchyma cells, while the female plant had a hollow pith. The result is important to farmers who are otherwise discouraged from having a plantation of C. papaya for fear of cultivating more of the fruitless male plants which will lead to low fruit productivity and less income.
Keywords: Sex determination, Carica papaya, morphology, anatomy, seedling-juvenile stage