Dioscorea bulbifera,


CHAPTER ONE
INTRODUCTION
Dioscorea bulbifera, the air potato, is a species of true yam in the yam family, Dioscoreaceae. It is known as varahi in Sanskrit, kaachil in Malayalam and dukkar kand in Marathi. It is native to Africa, southern Asia (India, China, Japan, Philippines, Indonesia, etc.) and northern Australia. It is widely cultivated and has escaped to become naturalized in many regions (Latin America, the West Indies, the southeastern United States, and various oceanic islands.
Air Potato has a winter dormant period when the stems die back to the ground. After dormancy, the underground tubers give rise to stems which quickly grow, often reaching up to 70 feet long by the end of the growing season.
The vine’s stem is herbaceous, not woody and round. The large leaves are up to 8 inches long and are heart-shaped (cordate). The leaf blade’s basal lobes are rounded. Leaf veins radiate from a single point. The leaves have long stems (petioles), and are alternate on the stem. Air Potato flowers are small, greenish and fragrant, hanging in relatively long clusters (panicles and spikes) up to 4 inches long. The fruit is a capsule of seeds. Air potato plants produce “aerial tubers” that are attached closely to the stems where leaves attach to the stem (axil). These air potatoes are grayish and somewhat irregular. Tubers also grow underground where they may be larger.
JUSTIFICATION
The scope of study is necessitated by the need to investigate the effect of discora bulbiferia on albino whister rats
LIMITATION
The work is limited by lack of availability of space, time and lack of research material on the above topic.
AIM/OBJECTIVES
The aim of study is to investigate the antidyslipidemic effect of dioscora bulbiferia on albino wistar rats, thus other objectives includes;
1. To find the effect of disocora bulbieria on albino wistar rats
2. To find the feeding habits of albino wistar rats
3. to find out the effect of antidyslipidemic on albino wistar rats,
3. to profer solutions to the effects of disocora bulbifera on albino rats.

CHAPTER TWO:
LITERATURE REVIEW
AIR POTATOES Dioscorea bulbifera

Florida is foster home to another invasive non-native Dioscorea, the water yam (= winged yam) Dioscorea alata. D. bulbifera and D. alata are superficially similar in appearance but distinguishing the two is straightforward. D. alata has a stem that is squarish in cross-section with wide ridges or wings, whereas the D. bulbifera stem is round in cross-section. Leaves are opposite in D. alata and alternate in D. bulbifera. The underground tubers of D. alata are also enormous, some weighing more than 45 kg, whereas the undergroind tubers D. bulbifera are small and may even be absent altogether (Langeland and Burks 1998).
Non-native Dioscorea species in Florida may also be mistaken for either of two native wild yams, D. floridana and D. quarternata. The native plants are only infrequently encountered in north and west Florida hammocks and floodplains. Where overlap with the exotic species occurs, the lack of aerial tubers in the native species can aid in identification (Langeland and Burks 1998).
REPRODUCTION:
Dioscorea bulbifera can propagate through both sexual and asexual means, In Florida, flowering is rare and sexual reproduction is therefore only a minor contributor to propagation of the species.
Dioscorea species are dioecious, with male and female flowers occurring in separate plants. Flowering is uncommon in the Florida populations but the flowering that does occur takes place in summer. Pollination is dependent on insects, commonly thrips, and the seeds are wind dispersed (Langeland and Burks 1998, Hammer 1998).
The chief means of reproduction in D. bulbifera is asexual and is dependant on vegetative growth from underground tubers and above-ground bulbils. Tubers and bulbils generally sprout in the spring and the new shoots often climb the dead stems of the previous year to reach the tree canopy. In the summer (June-July), a large number of new bulbils are produced which fall to the ground in late August. By the time seasonal stem die-back begins around October, a single vine may have put out as many as 200 bulbils (swww.killerplants.com 2004).
EMBRYOLOGY:
In areas where they are produced, Dioscorea bulbifera seeds are wind-dispersed (Hammer, 1998). Even where flowering occurs more regularly, sexual reproduction via seed is still likely of secondary importance. Seeds of D. bulbifera and other members of the genus are believed to undergo an obligate dormancy period of several months before they germinate. This strategy is probbably an evolutionary adaptation to ensure the presence of viable seeds in the seed bank when breaks in forest canopy cover occur. A laboratory germination regime for viable, non-dormant D. bulbifera seeds indicates that germination occurs in approximately 21 days at 30°C (Ellis et al. 1985).
Bulbils can last a year or more on the ground and still sprout, and soil contact in not necessary for sprouting. They also float and may be dispersed by flood waters and appear to be little impacted by feeding from raccoons, feral pigs, and other animals (Coursey 1967, Morisawa, 1999).
Air potato is one such non-native, invasive plant. This vine can grow eight inches a day and produces large numbers of potato-like growths that sprout new plants.
AERIEL YAM (DISCOREABULBIFERA) CULTIVATION IN NIGERIA

Aerial yam (Discoreabulbifera) belongs to Discoreae species, in Nigeria the aerial yam plants are predominantly noticed in some parts of the country which include Ibadan, oyo, Ogbomosho, Ile Ife, Ile Oluji, Ikire and Akure. It grows in a wide range of soils and most varieties require long rainy seasons. The Planting procedure include planting the bulbils or tubers either whole or small pieces, the tubers produced by the plants grown from bulbils are usually very small in the first year and often used as sets for planting the following year to produce edible tubers of a reasonable size. The tubers are occasionally used for the production of flour, they are also used has food in times of scarcity, but detoxification is necessary and this is done by soaking in water or prolong boiling before they are safe to consume and are very useful medicinally.
Wild yam(Discoreavillosa) is a plant native to North America, Mexico and Asia. In Nigeria the wild yam plants are predominantly seen in western part of the country like Owo, Oyo, Ogbomosho, Ikire Ile -Ife. It is believed to bea wonderful, natural hormone regulator. The herb
contains compound that are similar to female hormones which are helpful for female disorders. It contains natural steroid called dehydro-epiandrosterone(DHEA) that is said to rejuvenate and give vigor to love making. It is also considered to be a liver cleaner,it is has sometimes been called one of the best natural relievers of jaundice, and nausea.
There are many species of the genus discoreaa and lot of research work has been done on them but wild yam(Discorea villosa) and aerial yam(Discorea bulbifera) have not been investigated for their Rheological properties. The essence of the study is to carry out the rheological properties of the two varieties of the yam, wild yam(Discoreavillosa) and aerial yam(Discoreabulbifera).

CHAPTER THREE
MATERIAL
Material used for the study includes;
-animal cage
-Albino wistar rat
-weighing balance
-Dioscorea bulbifera
-markers
-masking tape
-animal feed (Rat feed)
-plates
-water
-stone
-tylaxopol
-grinder
-padlock/keys
-animal fats (high fat diet)
-saw dust
-tables, etc

CONCLUSION
Air potato is a member of the yam family (Dioscoreaceae). Yams are cultivated for their edible underground tubers in western Africa, where they are important commodities. However, uncultivated species—such as air potato—are generally bitter and even poisonous. Air potato is a vigorously twining herbaceous vine, often arising from an underground tuber. Freely branching stems grow to 60 ft. in length. Stems are round or slightly angled in cross section and twine to the left (counter-clockwise). Aerial tubers (bulbils) freely form in leaf axils. Bulbils are usually roundish with mostly smooth surfaces, and grow up to 5 in. x 4 in. Leaves are long petioled (stalked), alternate; blades to 8 in. or more long, broadly heart shaped, with basal lobes usually rounded and with arching veins all originating from one point. Flowers are rare (in Florida), small, and fragrant, with male and female arising from leaf axils on separate plants (i.e., a dioecious species) in panicles or spikes to 4 in. long. Fruit is a capsule; seeds are partially winged.

REFERENCES
Coursey, D.G. 1967. Yams: an account of the nature, origins, cultivation, and
utilization of the useful members of Dioscoraceae. London: Longmans,
Green and Co. Ltd. 230 pp.
Ellis R.H, Hong T.D., and E.H. Roberts. 1985. Handbook of seed technology for
genebanks – Volume II. Compendium of specific germination information and test recommendations. International Board for Plant Genetic Resources, Rome. Available online.
Hammer, R.L. 1998. Diagnosis: Dioscorea. Wildland Weeds:8-10.

Horvitz C.C., Pascarella J.B., McMann S., Freedman A., and R.H. Hofstetter.
1998. Functional roles of invasive non-indigenous plants in hurricane-
affected subtropical hardwood forests. Ecological Applications. 8:947-974.

Langeland K.A. 2001. Natural Area Weeds: Air Potato (Dioscorea bulbifera).
UF/IFAS Document SS AGR 164. 4 pp. Available online.

Langeland K.A. and K. Craddock Burks. 1998. Identification and Biology of
Non-Native Plants in Florida’s Natural Areas, IFAS Publication SP 257. University of Florida, Gainesville. 165 pp.

Morisawa T.L. 1999. Weed Notes: Dioscorea bulbifera, D. alata, D.
sansibarensis. The Nature Conservancy. Wildland Invasive Species Program.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s