Acuminata Var Research Articles

Molecular analysis of genetic stability in long-term micropropagated shoots of banana using RAPD and ISSR markers

A large number of micropropagated plantlets of banana, Musa acuminata var. Nanjanagudu Rasabale (NR), that were developed from axillary shoot bud explants over 10 years ago were screened for genetic variation, if any, using RAPD (Random Amplified Polymorphic DNA) and ISSR (Inter-Simple Sequence Repeats) markers. Of the 4000 in vitro plantlets, 11 were used for screening that involved shoot cultures with distinct variation in morphological characteristics (morphotypes). Similarly, the mother maintained in the field was also subjected for genetic analysis. Out of the 50 RAPD and 25 ISSR primers screened, 30 RAPD and 5 ISSR primers produced totally 424 clear, distinct and reproducible band classes resulting in a total of 5088 bands where the banding patterns for each primer was highly uniform and comparable to the field-grown mother clone from which the cultures had been established. These results indicate that the micropropagation protocol developed by us for rapid in vitro multiplication is appropriate and applicable for clonal propagation of banana var. NR over a long period. This is the first report on the use of genetic markers to establish genetic fidelity of long-term micropropagated banana using RAPD and ISSR.

Effects of Wind on the Allometry of Two Species of Plants in an Elfin Cloud Forest

ABSTRACTThigmomorphogenesis includes the effects of mechanical perturbation on plant growth. To test whether thigmomorphogenesis is evident at different scales within plants, we investigated the effect of wind on allometric relationships between specific plant parts. We chose two species from the elfin cloud forest of Puerto Rico that have contrasting growth habits, the shrub Clibadiun erosum (Asteraceae) and the palm Prestoea acuminata var. montana (Arecaceae), and subjected them to barrier‐protected and wind‐exposed treatments. For C. erosum, we compared the allometry of stems and branches against three allometric models that predict that plant height or branch length increases at the 1, 2/3, and 1/2 power of stem diameter. Only the geometric similarity model (scaling exponent of 1) seemed to hold when plants were exposed to the wind. We found relatively fewer leaves per number of branches produced and fewer leaves per increment of branch diameter in the plants of C. erosum exposed to the wind. Mean petiole length ratios (petiole length/basal radius) of P. acuminata were higher on leaves of barrier‐protected plants for both simple and compound leaves, indicating that petioles were stouter and mechanically safer in the wind‐exposed plants. We suggest that alteration of the allometric relationships of plant parts, organs, or plant modules (stems and branches of C. erosum and leaves of P. acuminata) and alteration of the number of plant parts (leaves and branches of C. erosum) are adaptive responses resulting from the mechanical perturbation induced by wind in the elfin forest.

Damage and Recovery of Riparian Sierra Palms after Hurricane Georges: Influence of Topography and Biotic Characteristics

ABSTRACTTropical forests are often shaped by disturbance events, especially in regions where hurricanes and other severe storms occur. We studied the effects of Hurricane Georges (September 1998) on the sierra palm (Prestoea acuminata var. montana) in the Luquillo Mountains of Puerto Rico. We established riparian transects along two headwater streams that were similar in size and location, but differed in riparian tree species composition and land‐use history. Following Hurricane Georges, sierra palms were surveyed periodically for damage and recovery (measured by initial loss and subsequent regrowth of palm leaves), tree height, sun exposure, and production of inflorescences and infructescences. Palm height had the highest association with damage, with most damage occurring to canopy palms. Palm recovery (4 mo and 10 mo post‐hurricane) was associated with high tree density, indicating that sun exposure was not limiting. Hurricane Georges likely reduced production of flowers and fruits in sierra palms for at least 10 mo following the storm, although production of new leaves was rapid. Although palms recovered quickly from defoliation after the hurricane, decreased reproduction resulted in reduced availability of fruit for terrestrial and aquatic consumers.

A Strategy for Restoration of Montane Forest in Anthropogenic Fern Thickets in the Dominican Republic

Abstract Deforested tropical areas are often colonized by competitive ferns that inhibit forest succession. In thickets of such a fern (Dicranopteris pectinata), we investigated methods for initiating restoration of tropical montane forest in the Ébano Verde Scientific Reserve (Dominican Republic). In clearings in the thickets, growth and survivorship of 18 common early‐ and late‐successional woody species were tested, with and without fertilizer (poultry litter). Three years after sowing, life history did not affect survivorship, but early‐successional species grew faster than late‐successional species (height increase 153 ± 103 cm vs. 81 ± 67 cm [mean ± 1 SD]). Inga fagifolia, a late‐successional species, and Alchornea latifolia, an early‐successional species, had 160 ± 62 cm mean height increase, and low mortality rates (<4%). In contrast, four late‐successional species (Cyrilla racemiflora, Myrcia deflexa, Prestoea acuminata var. montana, and Mora abbottii), and one early‐successional species, Ocotea leucoxylon, had approximately 39% mortality and height increase of 43 ± 48 cm. Brunellia comocladifolia had high mortality (55%), but averaged 340 ± 201 cm height increase, and was the only species whose growth was improved by fertilization. Fertilization improved survivorship of only one species, Piper aduncum. After three years, soils in the clearings had low pH and available P and did not differ significantly from soils in thickets. However, based on the growth rates and survivorship of sown woody plants, these soils did not appear to be a barrier for restoration. Although a complementary study demonstrated substantial natural regeneration, active planting should be used to increase plant density and diversity, especially where natural regeneration is poor.

Habitat selection by the Puerto Rican yellow-chinned anole,Anolis gundlachi

Habitat selection can directly affect the fitness of an individual and the evolutionary dynamics of the population to which that organism belongs. We studied habitat use of the Puerto Rican yellow-chinned anole (Anolis gundlachi Peters, 1876) to examine whether this arboreal lizard uses its environment in a nonrandom manner. Males and females preferred woody vegetation substrates over nonwoody plants and sierra palms (Prestoea acuminata var. montana (Graham) A. Henderson and G. Galeano) as perching sites, and they also selected wider vegetation than what was randomly available. Selection for minimizing conspicuousness to potential predators and for increased locomotion capacity may help explain the preference for woody substrates and broader surfaces, respectively. Anolis gundlachi relies almost exclusively on visual cues for foraging and social interactions, and using wider perches also increases an individual's ability to scan a larger proportion of its territory. Our findings thus indicate that the nonrandom habitat use of free-ranging A. gundlachi leads to the selection of perching substrates that may increase performance of ecologically relevant capabilities.

Agrobacterium-mediated transformation of Musa acuminata cv. “Grand Nain” scalps by vacuum infiltration

Two Agrobacterium-mediated plant transformation protocols were evaluated for the generation of transgenic banana tissues ( Musa acuminata var. Grand Nain). Co-cultivation versus vacuum infiltration of meristematic banana tissues was compared. The binary vector pC2301 was used for the initial transformation and the histochemical detection of GUS. PCR assays demonstrated that the transformation protocol was successful. Infiltrated samples transformed with pCambia 2301 showed a wider GUS response than the co-cultivated tissues. The specific β-glucuronidase activity was also higher in the infiltrated tissues than in co-cultivated ones and was also comparable to that found in other work. The vector BIBAC2 (bearing a 50 kb insert of foreign gDNA) was also transformed with these protocols showing the potential of this procedure on future genomics for this cultivar.

Characterization of resistant starch type III from banana (Musa acuminata).

Banana starch (Musa acuminata var. Nandigobe) was evaluated for its use in generating resistant starch (RS) type III. Structural, physicochemical, and biological properties of these products were analyzed. The investigated process includes debranching of the native starch and retrogradation under different storage temperatures and starch concentrations. After enzymatic debranching, a high amount of low-molecular-weight polymers with a degree of polymerization between 10 and 35 glucose units beside a higher molecular weight fraction were found. The resulting products comprised RS contents of about 50%. After heat-moisture treatment, the RS yield increased up to 84%. Peak temperatures of about 145 degrees C found in DSC measurements pointed to a high thermal stability of the RS products. In vitro fermentations of the RS products, carried out with intestinal microflora of healthy humans, resulted in a molar ratio of acetate:propionate:butyrate of about 49:17:34. The established method allowed the production of a high-quality RS with prebiotic properties for health preventing applications.

Most AAL toxin-sensitive Nicotiana species are resistant to the tomato fungal pathogen Alternaria alternata f. sp. lycopersici.

The phytopathogenic fungus Alternaria alternata f. sp. lycopersici produces AAL toxins required to colonize susceptible tomato (Lycopersicon esculentum) plants. AAL toxins and fumonisins of the unrelated fungus Fusarium moniliforme are sphinganine-analog mycotoxins (SAMs), which are toxic for some plant species and mammalian cell lines. Insensitivity of tomato to SAMs is determined by the Alternaria stem canker gene 1 (Asc-1), and sensitivity is associated with a mutated Asc-1. We show that SAM-sensitive species occur at a low frequency in the Nicotiana genus and that candidate Asc-1 homologs are still present in those species. In Nicotiana spp., SAM-sensitivity and insensitivity also is mediated by a single codominant locus, suggesting that SAM-sensitive genotypes are host for A. alternata f. sp. lycopersici. Nicotiana umbratica plants homozygous for SAM-sensitivity are indeed susceptible to A. alternata f. sp. lycopersici. In contrast, SAM-sensitive genotypes of Nicotiana spegazzinii, Nicotiana acuminata var. acuminata, Nicotiana bonariensis, and Nicotiana langsdorffii are resistant to A. alternata f. sp. lycopersici infection concomitant with localized cell death. Additional (nonhost) resistance mechanisms to A. alternata f. sp. lycopersici that are not based on an insensitivity to SAMs are proposed to be present in Nicotiana species.

Lack of Ecotypic Differentiation: Plant Response to Elevation, Population Origin, and Wind in the Luquillo Mountains, Puerto Rico1

How important is ecotypic differentiation along elevational gradients in the tropics? Reciprocal transplants of two shrubs, Clibadium erosum (Asteraceae) and Psychotria berteriana (Rubiaceae), and a palm, Prestoea acuminata var. montana (Palmaceae), were used to test for the effect of environment and population origin on growth and physiology in the Luquillo Experimental Forest of Puerto Rico. Two sites were used, one at Pico del Este (1000 m in cloud forest) and one at El Verde (350 m in lower montane rain forest). At the cloud forest site, plastic barriers were erected around a subset of the plants to examine if protection from wind affected survival or biomass accumulation. Survival of C. erosum and P. berteriana was not affected by site, population origin, or the presence of barriers. For P. acuminata var. montana, survival was higher for plants with barriers, but not affected by site and population origin. Plants of C. erosum and P. berteriana at El Verde grew larger than at Pico del Este, but there was no effect of population origin or barrier treatment on biomass accumulation for these species. For P. acuminata var. montana, there was no effect of environment, population origin, or barrier treatment on biomass accumulation. Light-saturated photosynthetic rate (Amax) of C. erosum, P. berteriana, and P. acuminata var. montana, as well as leaf anatomical characteristics of C. erosum, were unaffected by environment, population origin, and barrier treatment. On balance, there seems to be little evidence of ecotypic differentiation in these species along the gradient.

Evaluation of promissory tree species for sheep feeding in The Highlands of Chiapas, Mexico

The main objective of this study consisted of evaluating the fodder potential of the foliage of Buddleia cordata, Montanoa leucantha subsp. arborescens, Erythrina chiapasana, Quercus rugosa and Alnus acuminata var. arguta, tree species present in The Highlands of Chiapas, Mexico, in order to select the best fodder and carry out an evaluation of the species with greatest potential in sheep feeding. The chemical composition results on a dry matter basis were as follows: the crude protein (CP) content ranged from 8.4% in Q. rugosa to 27.7% in M. leucantha. Neutral detergent fiber (NDF) ranged from 39.0% in M. leucantha to 58.3% in Q. rugosa and Acid detergent fiber (ADF) varied from 30.8% in M. leucantha to 56.8% in Q. rugosa; Gross energy (GE) contents were 3.0 kcal/g or even greater. Tannic acid was detected from 0.25 g/100 g in E. chiapasana to 1.1 g/100 g in Q. rugosa; there were no cyanogenic glucosides detected in the samples, and no alkaloids were encountered in Q. rugosa and A. acuminata, but E. chiapasana showed higher alkaloid content than the other trees. Q. rugosa had the highest foliage production (6.9 kg DM/plant/cut), while E. chiapasana had the lowest production (1.2 kg DM/plant/cut). In an in vivo intake and digestibility trial, the leaves of M. leucantha fed as a sole diet for sheep had the best composition values, higher ( P<0.05) in vivo dry matter intake (IVDMI-L) (628 g/day) and in vivo dry matter digestibility (IVDMD-L) (76%) of the five evaluated species. Therefore, the foliage of M. leucantha was included in the sheep's diet in a growth and digestion trial at 0%, 25% and 40% levels of inclusion replacing alfalfa ( M. sativa); in vivo CP intake (IVCPI-D) (106.9 g/day), in vivo CP digestibility (IVCPD-D) (67.5%), and live weight gain (LWG) (75 g/day) were higher ( P<0.05) in sheep fed with diets including M. leucantha leaves at 40% level of inclusion. In vivo DM intake (IVDMI-D), in vivo DE intake (IVDEI-D) and in vivo NDF intake (IVNDFI-D), as well as in vivo DM digestibility (IVDMD-D), in vivo DE digestibility (IVDED-D), in vivo NDF digestibility (IVNDFD-D) and wool production (WP), were similar ( P>0.05) in diets including 0%, 25% and 40% of Montanoa leucantha leaves.

Revision of the NMR Assignments of Pterostilbene and of Dihydrodehydrodiconieferyl alcohol: Cytotoxic Constituents fromAnogeissus acuminata

Abstract Further phytochemical work on Anogeissus acuminata var. lanceolata (Combretaceae) led to the isolation of pterostilbene (1), dihydrodehydrodiconiferyl alcohol (2), and conocarpan (3). The structure of these compounds were determined by spectroscopic means, mainly through 1D and 2D NMR experiments. A revision of some of the 13C NMR chemical shifts of 1 and 2 were made possible by HETCOR, FLOCK, and selective INEPT experiments. Homonuclear spin-decoupling and 1H-1H COSY experiments also enabled the precise assignment of the 1H NMR chemical shifts of 2. Compounds 1–3 exhibited in vitro cytotoxicity in various cancer cell lines. This is the first isolation of 1–3 from Anogeissus.

Somatic Embryogenesis in Three Magnolia Species

Cultures were initiated from immature seeds of three species of magnolia: sweetbay magnolia (Magnolia virginiana L.), fraser magnolia (M. fraseri Walt.) and yellow cucumbertree [M. acuminata var. cordata (Michx.) Sarg.]. Immature seeds were bisected longitudinally and cultured on a solidified conditioning medium containing 2 mg 2,4-D/liter, 0.25 mg BA/liter, 40 g sucrose/liter, and 1 g casein hydrolysate/liter. Cultures were maintained in the dark at 22C and transferred to fresh medium at monthly intervals. Within 2 months of culture, somatic embryos or proembryogenic masses proliferated from one end of the endosperm mass. Somatic embryos and proembryogenic masses of each species were cultured on a hormone-free version of the conditioning medium to complete maturation and then transferred to the same hormone-free medium, minus casein hydrolysate, to initiate germination. Germinants were transferred to a hormone-free plantlet development medium for conversion. Plantlets of all three species survived transfer to soil mix and continued to grow. Chemical names used: (2,4 -dichlorophenoxy) acetic acid (2,4-D), N- (phenylmethyl)-1H-purin-6-amine (BA).

SOME ANEUPLOIDS IN INDIAN CHAROPHYTA

SUMMARY Aneuploid chromosome numbers have been found in Indian material of Chara zeylanica var. zeylanica f. elegans (A.Br. & T.F.A.) Gr. & J.Gr. (n = 48) and Nitella acuminata var. acuminata f. belangari (A. Br.) R.D.W. (n = 29). The cytotaxonomy of the C. zeylanica complex has been discussed with reference to the antheridial scutae number. On karyotypic grounds N. acuminata f. belangari has been given the status of ‘variety’.

OBSERVATIONS ON NITELLA ACUMINATA FROM SOUTHWESTERN UNITED STATES AND NORTHERN MEXICO1

SUMMARYMorphological and cytological analyses of several specimens of the genus Nitella suggest that species described as N. stellaris, N. lindheimeri, N. gollmeriana, and N. mexicana and some forms reported as N. acuminata var. subglomerata represent a single taxon in the N. acuminata species group. Cytological examination revealed a chromosome number of n = 9 in the specimens from the study area but N. acuminata is known to display n = 18 chromosomes in other regions of North America and on oilier continents. Hypotheses regarding the origin and significance of this polyploidy are discussed. The habitats supporting N. acuminata (n = 9) in the study area show some features which are in contrast to those of habitats supporting the species (n = 18) in other areas of North America.

DIFFERENTIAL PHYTOTOXICITY OF ATRAZINE AND AMETRYNE TO BANANAS*

Summary. In field screening trials for bananas (Musa acuminata var. Dwarf Cavendish) in Hawaii, ametryne (2‐methylthio‐4‐ethylamino‐6‐isopropylamino‐s‐triazine) was less phytotoxic to bananas than atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine). Sand culture experiments showed that both herbicides were equally injurious to banana plants. Differential degradation of the herbicides by the plants did not account for the phytotoxicity observed. Both herbicides were partly metabolized by the plant to their common hydroxyl derivative (hydroxyatrazine) and two other unidentified metabolites after 3 and 7 days of exposure to nutrient solution containing 14C‐labelled ametryne and atrazine.Phytotoxicity was directly related to leachability of the herbicides and negatively related to adsorption capacity of each soil for the herbicides. Organic matter content seemed to be correlated to the response observed. It was postulated that phytotoxicity in the field may have been attributed to differential location of the herbicide in relation to the roots.

長野県飯綱高原大座法師池と論電ガ池のプランクトン

Plankton was studied on the basis of three samples which were collected by Prof. M. Tsuda in Daizabozu-ike Pond and Rondenga-ike Pond in the Iizuna Heights, Nagano Prefecture, in August, 1965.Thirty eight species of phytoplankton and seventeen species of zooplankton were found in Daizabozu-ike Pond sample, the abundant species being Melosira italica (Bacillariophyta) and Keratella cochlearis (Rotifera). The plankton of this pond are mostly cosmopolitan. Some species such as Nostoc paldosum, Melosira distans and others are alpine species.In Rondenga-ike Pond sample, fifty four species of plankton were found, one half of which being same as the species of Daizabozu-ike Pond. The dominant components are Melosira italica, M. distans (Bacillariophyta) and Difflugia acuminata var. inflata, Phryganella haemispherica (Protozoa).At the shore of Rondenga-ike Pond, the water bloom was seen forming the reddish brown scum at water surface. It seems that the scum is formed by Peridinium Elpatiewskyi.

NOTES ON ASIATIC ORCHIDS III

Some of these new combinations, namely, Eulophia bicallosa, Malaxis acuminata var. biloba, Herminium monophyllum and Liparis petiolata are based on the manuscript list of Nepalese orchids compiled by Mr. J. E. Dandy, Keeper of Botany at the British Museum (Natural History). We are indebted to him for his help and for suggesting that we should publish these names.