Abstract
One-seeded fruit of peanut (Fig. 2) is induced by the abortion of one of two ovules due to fertilization failure (Fig. 3). So far as the varieties used in this investigation are concerned, the abortion exceeded slightly at the upper ovule over that at the lower one and was about 8∼10% in sum in the case of normal flower, whereas a greater frequent occurrence of abortion was found at the lower ovule and resulted in one-seeded fruit of 15∼20% as total (Table 2, 3) in the case of underground flowers (Fig. 1). Besides the one ovule abortion, the underground flower contains also a tremendously high rate of non-fertilization of two ovules involved, inducing the failure of gynophore formation (Table 5) Such total damage of two ovules was caused by the extreme scarcity of pollen-set on stigma as well as the imperfect elongation of style retaining the stigma within staminai tube (Table 6). The above-mentioned behavior performed by underground flowers may be explained from their special surroundings and the abnormal flower structure.
