tailieunhanh - Báo cáo lâm nghiệp: "Pollen-limited seed set in ( Tamarindus indica L.)"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Pollen-limited seed set in ( Tamarindus indica L.). | 56s Ann. Sci. For. 1989 46 suppl. 56S-59S Forest Tree Physiology E. Dreyer et al. eds. Elsevier INRA Pollen-limited seed set in pods of tamarind Tamarindus indica L. . Thimmaraju V. Bhaskar and K. Usha University of Agricultural Sciences Gandhi Krishi Vignana Kendra Bangalore 560 065 India Introduction A negatively skewed distribution of seeds per pod where the frequency of manyseeded pods is higher than that of the few seeded ones is a common feature of a majority of the multiovuled species Lee and Bazaaz 1982 However disturbances of this negatively skewed distribution have been reported for certain other species. The adaptive reasons for and mechanisms causing such deviations are less well known. In this paper we have analyzed 3 factors causing positively skewed distribution PSD of seeds per pod in T. indica 1 resource limitation 2 post-fertilization abortion of seeds and 3 pollen grain limitation. Materials and Methods Tamarindus indica L. Caesalpinae is a tropical tree cultivated for the pulp of the fruit which is used in culinary preparations. It exhibits varied patterns of seed distributions per pod of which PSD is the most common. Data were gathered from 4 tamarind trees in and around Gandhi Kri-shi Vignana Kendra Campus of the University of Agricultural Sciences Bangalore India using 50 flowers for each set of observations 1 pollen grains stigma of intact and abscised flowers 2 number of fertilized ovules 3 percentage of flowers set into fruits and 4 resource limitation selected branches of approximately equal size were defoliated to an extent of 25 n 10 50 n 10 and 75 n 10 and fruit set in these was compared with control branches 5 effect of pollen quality flowers n 50 were either self-pollinated artificially crossed with pollen from different trees or allowed to pollinate naturally. The seed set percentage of these was compared. Results Pod and seed set were low in tamarind about 25 of the flowers set pods and most contained few 1-4 seeds Fig. 1 . .