Correlations between reproductive mode and habitat

72 The three parameters are related to temperatures. In general, triploid plants grow in low temperature sites than diploid plants. In many species of Diplazium from West Malesia, however, there are not any strick correlation between ploidy level and habitat gradient. All species with only diploid type, viz. D. accedens, D. petiolare, D. polypodioides, D, speciosum, D. sorzogonense, D. spiniferum and D. umbrosum, are growing from 420 m to 1500 m. Species with two different ploidy levels are growing on almost the same elevation. The tetraploid D. crenatoserratum were collected from 20 – 150 m sea level where the triploid one was also found in the range, 55 m sea level. Triploid and tetraploid D. angustipinna were found at the same altidude, 440 m. In contrary, pentaploid D. batuayauense was growing at 440 m, whereas the tetraploid plant was found at 450 m. Overlap distribution was seen in D. cordifolium . Tetraploid D. cordifolium was growing from 240 m to 1200 m, whereas pentaploid plants were occuring from 1000 m to 1200 m. As has been mentioned above, there are only few species that has a correlation between ploidy levels and habitat gradient, such is D. riparium and D. xiphophyllum. Some species of West Malesian Diplazium showed a correlation between ploidy level and altitute gradient. Diploid D. riparium was found at 150 m, whereas the triploid plant was at 280 m. Tetraploid plants of D. pallidum were only found above 1000 m, whereas those diploid were growing from 30 m to 250 m. Triploid and tetraploid D. silvaticum are growing at ca. 20 m and ca. 280 m, respectively. The hexaploid D. xiphophyllum was found at higher altitude than those of tetraploid and diploid.

5.3.4. Correlations between reproductive mode and habitat

Some studies have found distinct correlation between reproductive mode and habitat Holbrook-Walker Lloyd 1973; Lloyd 1974. Sexual reproduction is most frequent in moist habitats, whereas apomictic reproduction is more common in ferns growing in xeric habitats Tryon 1968. However, some apomictic species do not live in xeric habitats, for example some Japanese Diplazium Takamiya et al 1999 and Cornopteris christenseniana Park Kato 2003. 73 Table 5.2. Polyploid series of Diplazium in West Malesia Based on Present Study Ploidy Level Species 2X 3X 4X 5X 6X 8X D. accedens D. aquibasale D. asymmetricum D. bantamense D. batuayauense D. cordifolium D. crenatoseratum D. dilatatum D. donianum D. esculentum D. halimunense D. hewittii D. loerzingii D. pallidum D. petiolare D. polypodioides D. procumbens D. profluens D. porphyrorachis D. riparium D. simplicivenium D. silvaticum D. speciosum D. procumbens D. sorzogonense D. subpolypodioides D. spiniferum D. subserratum D. subvirescens D. tomentosum D. umbrosum D. xiphophyllum D. wahauense V - - - - - - - - V - - V V V V - - - V - - V - V V V V - V V V - - - V - - - V V - - V V V - - - V - - V V V - V - - - V V - - - - - V - V V V V V V - - - - V - - - V V - - V - - - - - V - V - V V - - - - V V - - - - - - - - - - - - - - - - - - - - - - - V - - - - - - - - V - - - - - - - - - - - - - - - - - - - - - - - - - V - - - - V - V - - - - - - - - - - - - - - - - - - - - - - - - - - - TOTAL 15 13 15 3 2 2 Notes: V Present study V Praptosuwiryo Darnaedi 1994 74 Figure 5.1. Somatic chromosome of Diplazium. a. D. accedens var. accedens , 2n = 82 ; b. D. accedens var. spinosum, 2n = 82; c. D. angustipinna, 2n = 164 TNgP 1906b; d. D. angustipinna , 2n = 123; e. D. spiniferum TNgP 1896a, 2n = 82; f. D. halimuense, 2n=123 TNgP 2341b. Bar = 3 m. 75 Figure 5.2. Somatic chromosome Diplazium. a. D. umbrosum, 2n = 82 TNgP1348 ; b. D. petiolare 2n = 82 TT993-3, c. D. tomentosum, 2n = 82 TNgP 2336b; d. D. tomentosum, 2n = 205 TNgP1722; e. D. tomentosum, 2n = 164 TNgP2066; f. D. asymmetricum, 2n=123 TNgP 1094. Bar = 3 m. 76 Figure 5.3. Somatic chromosomes of Diplazium. a. D. xiphophyllum TNgP, 2n = 246; b. D. xiphophyllum TD902, 2n = 164; c. D. xiphopyllum TNgP1841 , 2n = 82; d. D. batuayauense TNgP 1927, 2n = 123; e. D. porphyrorachis TNgP1885, 2n = 164. Bar = 3 m. 77 Figure 5.4. Somatic chromosomes of Diplazium. a. D. subserratum, 2n = 82 TNgP1463, b. 2n = 123 TNgP2287, c. 2n = 164 TNgP1379; d. D. subpolypodioides, 2n = 82 TNgP2292; e. D. procumbens, 2n = 123 TNgP1348. Bar = 3 m. 78 Figure 5.5. Somatic chromosomes of Diplazium cordifolium. a. 2n = 164 TNgP1735; b. 2n = 205 TNgP1204; c. 2n = 246 TNgP1201; d. 2n = 328 TNgP 1926b. Bar = 3 m. 79 Figure 5.6. Somatic chromosomes of Diplazium. a. D. pallidum, 2n = 82 TNgP1406; b. D. pallidum 2n = 164 TNgP1764; c. D. riparium, 2n = 123 TNgP 1847; d. D. polypodioides, 2n = 82 TNgP2285; e. D. dilatatum, 2n = 123 TNgP1073; f. D. speciosum, 2n=82 TNgP1359 . Bar = 3 m. 80 Reproductive studies on Diplazium from West Malesia showed that both the sexual and apomictic species can occur in the moist habitats. The apogamous triploid D. procumbens and D. simplicivenium are found in dryland areas of the slopes on Mt. Gede-Pangrangrango and Mt. Salak in which have the relatively high amount of rainfall ca. 200 mm per month in October - May. The apogamous pentaploid D. batuayauense was also growing at the moist soil in shady place in the forest. The sexual and apogamous tetraploid of D. bantamense are found at the relatively same habitats condition. The two race are found at the moist humus-rich soil of the dryland areas of Cangkuang forest in Mt. Salak. These results revealed that there are not distinct correlation betweed the reproductive mode and habitats in West Malesian Diplazium. In many ferns reproductive barriers are likely to exist between polyploid and their ancestors. This increases the potential for the development of their spatial segregation Vogel et al 1999. Some researchs demonstrate that microenvironment habitat selection is partially responsible for maintaining the separation of different cytotypes in ferns and flowering plants Kumaret et al 1987. In West Malesian Diplazium the separation between polyploid and their ancestors have not been seen clearly. Beacuse most of species with seri ploidy have not been examined well their mode of reproductive by sampling many individual plants. Moreover, the ancestors of the many polyploid species observed have not been found, their ancestors diploid types have not been found yet. The diploid of D. bantamense, D. simplicivenium, D. procumbens, and D. asymmetricum , for example, have not been recognized their existence. Therefore further study on cytology and the mode reproductive of West Malesian Diplazium to understand its speciation mechanism are needed. 81

5.4. Conclussions