Seeds of clones are termed clonal seeds. There are different kinds of clonal seeds – monoclonal, polyclonal, legitimate and illegitimate. Monoclonal seeds of clone Tjir 1 which gave rise to seedlings superior to seedlings from ordinary, unselected seeds were once encouraged for planting extensively in our country. Evolution of newer, improved planting materials then progressively replaced Tjir 1 clonal seedlings. Hybrid polyclonal seeds collected from approved polyclonal seed gardens are the only seed material recommended for planting now. For production of good quality polyclonal seeds, gardens have been established in Kanyakumari district. Polyclonal garden seeds in the name Prang Besar Isolated Garden (PBIG) seeds from Malaysia used to find limited market in India until a few decades ago.
Seeds collected from clonal stands are known as clonal seeds.In olden days monoclonal seeds of single mother clones such as Tjir 1, not contaminated by crossing with seedling rubber or undesirable male parent clones,had been extensively used as improved planting materials. Now only clonal seeds of polyclonal origin which can be expected to possess significant hybrid vigour are accepted. Ployclonal seeds of good clones are planted in such seed gardens mixe as per specific designs. For prevention of pollen contamination from rubber trees of neighbouring area, an isolation belt of 100 meters width is provided all around. Polyclonal seeds give rise to seedling of good vigour and growth. Compared to buddings, they are easier to establish and maintain. The trunk of seedling is much larger than those of budded trees. Owing to the inherent genetic variability, they are relatively less suceptible to wind damange and disease. However, the general yield levels are far lower than selected modern clones. The high tree to tree variability in growth and yield makes it necessary to adopt thorough selection of seedling for planting based on initial viour, high initial planting density in the main field and subsequent judicious thinning out of weakilings and poor yielders in a phased manner. Still, the trees exhibit proneness to tapping panel dryness. The average annual yield is 1200 to 1300 kg/ha/yr.