Nodulation,biomass and nitrogen content in Sesbania species

Sesbania rostrata developed nitrogen fixing nodules on the stem after spraying the plants with the bacterial culture TCSR 1. The number of stem nodules at 55 days after sowing was about 1200. Plants with stem nodules had a significantly reduced number of root nodules. The biomass of S. rostrata was comparable to the locally well adapted non-stem nodulating species S. aculeata. The %N and total nitrogen content were highest in S. rostrata compared to the other three species studied.     

The biogeography of species,with special reference to ferns

An important element of the biogeography of species is the geographic aspects of speciation. The geography of species has a role in the processes of speciation which have a reciprocal role in species geography. The homosporous ferns provide an especially favorable group for biogeographic studies because nearly all species have an equivalent capacity for dispersal and migration. Species ranges are based on the ecology of the environment, rather than on animal vectors of dispersal or pollination. However, with allowance for these differences, the processes of geographic speciation are basically the same in ferns and other vascular plants, although often on a broader geographic scale in the ferns. Speciation most frequently produces a new species with a small range, which can rapidly expand to occupy the geography of the environment to which the species is adapted. The members of a closely related speciesgroup retain their morphological and geographic relations for a relatively short time. With speciation, changes in distribution, and extinction, the original relations of the species and the biogeographical history of the group will be lost. High regional species diversity occurs in the wet mountainous regions of the tropics, where there is greatest ecological diversity and maximal opportunities for speciation and persistence.     

Studies on mycobacteria isolated from animals, with special reference to the agglutination test

Ninety-three strains of slowly-growing mycobacteria were studied biochemically. Ninety of these were isolated from animals (pigs, cattle, dog and poultry) and three from dust and sawdust-bedding in a pighouse. One strain from a lymph node of a pig was identified as M. gordonae. Ninety-two strains fitted into the M. aviam-intracellulare complex. Of the 92 biochemically confirmed M. avium-intracellulare strains, 78 were tested serologically ad modum Schaefer. Of 73 strains from pigs, one was serotype 1, fifty serotype 2 and eight serotype 8, while two could not be type and twelve were autoagglutinable. Three strains from pighouse environment were serotype 8 and two from cattle and a dog were both serotype 2. A slight modification of Schaefer's agglutination method, using smaller amounts of antigen and antiserum, was developed.     

Nodulation of Sesbania species by Rhizobium (Agrobacterium) strain IRBG74 and other rhizobia

Concatenated sequence analysis with 16S rRNA, rpoB and fusA genes identified a bacterial strain (IRBG74) isolated from root nodules of the aquatic legume Sesbania cannabina as a close relative of the plant pathogen Rhizobium radiobacter (syn. Agrobacterium tumefaciens ). However, DNA:DNA hybridization with R. radiobacter , R. rubi , R. vitis and R. huautlense gave only 44%, 5%, 8% and 8% similarity respectively, suggesting that IRBG74 is potentially a new species. Additionally, it contained no vir genes and lacked tumour-forming ability, but harboured a sym -plasmid containing nifH and nodA genes similar to those in other Sesbania symbionts. Indeed, IRBG74 effectively nodulated S. cannabina and seven other Sesbania spp. that nodulate with Ensifer ( Sinorhizobium )/ Rhizobium strains with similar nodA genes to IRBG74, but not species that nodulate with Azorhizobium or Mesorhizobium . Light and electron microscopy revealed that IRBG74 infected Sesbania spp. via lateral root junctions under flooded conditions, but via root hairs under non-flooded conditions. Thus, IRBG74 is the first confirmed legume-nodulating symbiont from the Rhizobium ( Agrobacterium ) clade. Cross-inoculation studies with various Sesbania symbionts showed that S. cannabina could form fully effective symbioses with strains in the genera Rhizobium and Ensifer , only ineffective ones with Azorhizobium strains, and either partially effective ( Mesorhizobium huakii ) or ineffective ( Mesorhizobium plurifarium ) symbioses with Mesorhizobium . These data are discussed in terms of the molecular phylogeny of Sesbania and its symbionts.     

Some studies on Nigerian palm wine with special reference to yeasts

The identification and enumeration of yeasts and the effect of chemical preservatives on the yeast load in Nigerian palm wine have been studied. Yeast found largely belong to the genus Saccharomyces. Other genera found were Candida, Endomycopsis, Hansenula, Kloeckera, Pichia, Saccharomycoides and Schizosaccharomyces. The viable yeast count ranged from 0.5 × 10⁷ cfu/ml to 4.2 × 10⁹ in both fresh Elaeis and Raphia spp. of palms. Yeasts in palm wine were least sensitive to sodium nitrate and most sensitive to sodium benzoate. The addition of these two chemical preservatives amongst others reduced the yeast count to 3.2 × 10⁸ (in Raphia sp.), and 4.1 × 10⁹ (in Elaeis sp.) with 0.025% sodium nitrate and 1.2 × 10⁶ (in Raphia sp.) and 1.9 × 10⁷ (in Elaeis sp.) with 0.1% sodium benzoate. The values of the yeast count in bottled and fresh palm wine were between 1.3 × 10³ cfu/ml to 9.8 × 10⁶ and 0.5 × 10⁷ to 4.2 × 10⁹, respectively. Maximum values of actual dry and theoretical yeast weights were 1.09 and 42 mg/ml, respectively.     

Pollen and ovule production in wind-pollinated species with special reference to Juncus

The reproductive biology of wind-pollinated species in terms of pollen and ovule production is rarely studied compared with zoophilous species, despite available hypotheses on the effect of growth form and life-history traits on reproductive investment. Here, we use published data and new data for species of Juncus and Luzula (Juncaceae) to test the hypotheses that, in wind-pollinated species, woody perennials should exhibit larger pollen–ovule (P/O) ratios than herbaceous species and that species with separate sexes have larger P/O ratios than homoecious species. In total, we report pollen and ovule production for 291 wind-pollinated species, including 19 Juncus and 5 Luzula species. Compared with other wind-pollinated species, Juncus exhibits unusually low P/O ratios (log P/O = 2.06 ± 0.46) because of high ovule production. We argue that the high ovule and seed production in Juncus, associated with frequent self-fertilization, may be beneficial in habitats preferred by the genus. In general, we found higher P/O ratios in woody perennials (log P/O = 4.37 ± 1.18) or in species with separate sexes (log P/O = 4.28 ± 1.12) than in herbaceous (log P/O = 3.51 ± 0.77) or homoecious (log P/O = 3.52 ± 0.80) species, respectively. However, when we analyzed woody perennials separately, we found no significant difference in P/O ratios between homoecious and nonhomoecious species. We argue that woody perennials, independent of dicliny, may be preferentially outcrossed and therefore exhibit decreased variation in mating systems compared with herbs. Because the degree of outcrossing correlates with P/O ratios, differences between homoecious and nonhomoecious woody perennials could be less pronounced.     

Cytogenetic studies on natural populations of grasshoppers with special reference to B-chromosomes

In Atractomorpha bedeli the frequencies of males with B-chromosomes in the males from the Tofuro-ato population were 21, 30, 32, 40, and 26%, respectively, over five years. Numbers of B's (0 to 7) in the primary spermatocytes were usually constant within the follicles but were variable among the follicles within the individuals. In males from the Okazyo-ato population, 35% contained B's in their primary spermatocytes. The cells of the gastric caeca were observed in 8 males with B's in the primary spermatocytes but no cells of the gastric caeca contained B's. Cells of ovariole walls and those of gastric caeca were analysed in 80 females from the same population; none of them contained B's. These facts indicate that B's are present in the germ line but absent in the somatic line. The difference between the germ line and the somatic one was explained on the basis of elimination of B's from the somatic cells. The inter-follicular variation in number of B's was ascribed to mitotic non-disjunction in the germ line prior to differentiation of the follicles.Contribution No. 86 from the Institute of Biology, Oita University.     

The probabilistic identification of Vibrio spp. isolated from surface seawater with special reference to Vibrio campbellii

A subset (n = 20) of 143 putative Vibrio spp. isolated from surface seawater samples collected along a transect from Barbados to Puerto Rico to Bermuda were included in a numerical taxonomy study. Fourteen strains were identified as Vibrio campbellii . It was concluded that V. campbellii occurs in the open ocean with high frequency, and probably represents an autochthonous species in surface waters of the Atlantic Ocean.     

Historical view of DNA replication studies, with special reference to Japan

Almost forty years after the key contributions to the field by Okazaki and coworkers that gave rise to the concept of leading and the lagging strand, we are still at the state of uncertainty about the proteins that replicate each strand. Perhaps, one main conclusion that should be drawn from the data currently available is that the protein architecture at the fork is more plastic than originally thought.     

Nodulation of acacia species by fast- and slow-growing tropical strains of Rhizobium

Thirteen Acacia species were classified into three groups according to effective nodulation response patterns with fast- and slow-growing tropical strains of Rhizobium. The first group nodulated effectively with slow-growing, cowpea-type Rhizobium strains; the second, with fast-growing Rhizobium strains; and the third, with both fast- and slow-growing Rhizobium strains. The Rhizobium requirements of the Acacia species of the second group were similar to those of Leucaena leucocephala.