Wednesday, June 30, 2010

Basic about Plants : Sexuality

.

How the sperm from one plant fertilizes the ovum of another, is the most important determinant of the making structure of plant populations. The morphology of the flower parts and their arrangement on the plant in turn controls the amount and distribution of genetic variation, a central element in the evolutionary process.

.

Perfect flower have both male ( androecium ) and female ( gynoecium ) reproductive structures.

Perfect flowers not necessary have petals or sepals. A complete flower is a perfect flower with petals and sepals.

Hermaphrodite refers to plants that have perfect flowers. In angiosperm terminology, a synonym is monoclinous, from the Greek word ‘one bed’.

.

Imperfect flower have either functionally male ( staminate ) or functionally female ( pistilate ) reproductive structures.

.

Monoecious refers to plants that have both male and female flowers on the same plant, from Greek word ‘one household’.

A monoecious that bear flowers of one sex at one time are called simultaneously or synchronously monoecious ; individuals that bear flowers of one sex at one time are called consecutively monoecious.

Protoandrous describes individuals that function first as males then change to females ; protogynous describes individuals that function first as female and then change to males.

.

Dioecious refers to plant that have separate male and female flowers. They are either gynoecious ( female plants ) or androecious ( male plants )

.

Polygamomonoecious or trimonoecious refer to plants with male, female and perfect flowers on the same plant.

.

Gynoecy refer to plants that are all females in a population, often regulated by environmental factors like temperature, photoperiod or water availability.

Friday, June 18, 2010

Confusing UBI

Ubi in Malay language refers to specialized root modified for storage of food or water. .Tuber it is.

.

There are not many varieties of edible tuberous roots that I know of. But in Malay term, the word ‘ubi’ is prefixed to almost all of it, i.e ubi kentang, ubi kayu, ubi keledek. This creates confusion lead many to conclude that they are from ‘ubi’ family. They are however, of very distinct family.

.

Ubi kentang 马铃薯 is potatoes, the tuberous root of Solanum tuberosum of the Solanaceae family ( nightshades family ). It is an herbaceous annual shrub.

.

Ubi kentang is suggested to originated from Peru, South America. However 99% of today’s cultivated potatoes are descendants of a subspecies indigenous to Chile. The Chilean subspecies, Solanum tuberosum ssp. tuberosum, is believed to be cultivated as long as 10,000 years ago.

.

The Spaniard brought it to Europe in 1536, soon spread to the rest of the world. The potatoes reached India in the late 16th and early 17th century, most likely aboard ships from Portugal. Then, it spread to the rest of Asia.

,

Potatoes contains vitamin C, vitamin B6, potassium and trace amounts of magnesium phosphorus, iron and zinc.

.

World production of potatoes was 314 million tones. China was the main producer with 70 million tones.

.
.
.

Ubi kayu 木薯 is cassava, root of Manihot esculenta, is a woody shrub of the Euphorbiaceae family ( spurge family ).

Ubi kayu is native to South America, presumably eastern Brazil.

.

Ubi kayu is an ancient crop species. Domestication began some 5000-7000 years BC. By the time the Europeans reached the New World, the crop was already cultivated in all of neotropical America. It was only centuries ago. The Portuguese traders carried the crop from its native America to Africa and then Asia.

.

The roots are very rich in starch, calcium, phosphorus and vitamin C. However they are poor in protein and other nutrients. In contrast, cassava leaves are a good source of protein

.

World production of cassava was estimated to be 184 million tones in 2002. The major production is Africa, with Nigeria lead as world’s largest producer.

.
.
.

Ubi keledek 番薯 is sweet potato, tuberous root of Ipomoea batatas, an herbaceous perennial vine belongs to the family Convolvulaceae family.

.

Sweet potatoes are native to South America, domesticated some 5000 years ago. Radiocarbon dating suggested it has been in Cook Islands around 1000 AD, possibly brought by Polynesians who had travelled to South America and back, and spread across Polynesians to New Zealand. Captain Cook and Sir Joseph Banks found the Maoris of NZ’s North Island growing sweet potato ( locally known as Kumara ) when they landed in 1769.

.

The Spaniard brought the sweet potatoes to the Philippines in the 16th century. From there the Portuguese spread it to East Indies and India. Sweet potatoes found it way to China in 1593, when a famine in Fujian province leads the people to search for alternative food from the Philippines. It was not until the 18th century that the sweet potatoes made its way into Japan, possibly through China.

.

The roots are rich in complex carbohydrates, dietary fiber, beta carotene, vitamin C, vitamin B6, calcium and iron. The leaves and shoots are also edible

.

World production of sweet potato is 127 million tones in 2004. China was the top producer.

Wednesday, June 9, 2010

Citrus is complicated

Citrus is a common term and genus of flowering plants in the rue family, Rutaceae.


The taxonomy of the genus is complex and the precise number of natural species is unclear, as many of the names species are clonally propagated hybrids. Some wild, true-breeding species are of hybrid species. Cultivated Citrus may be derived from as few as 4 ancestral species.

Citrus has been suggested to originated in S.E.Asia. Prior to human cultivation, it consisted of just few species : C. aurantifolia. C. maxima (), C. medica, C. reticulata (,橘), C. tifoliata / Poncirus trifolia (), C. australasica, C. australis, C. glauca, C. japonica / Fortunella japonica, C. halimii, C. indica, etc
















Some popular hybrids and cutivars : Grapefruit, sweet orange, Buddha’s hand, blood orange, Clementine, ponkan, tangerine, lime, lemon, etc













































Monday, June 7, 2010

Momordica

Momordica is a genus of about 80 species of annual or perennial herbaceous climber belong to the family Cucurbitaceae., natives to tropical and subtropical Africa, Asia and Australia.

.

Momordica charantia, bitter gourd 苦瓜is native to Africa, but long been used in Chinese folk medicine. The fruit has a distinct warty looking exterior with an oblong shape. It is hollow in cross-section, with a relatively thin layer of flesh surrounding a central seed cavity filled with large flat seeds and pith. Seeds and pith appear white in unripe fruits, ripening to red.

..

Bitter gourd comes in a variety of shapes and sizes. The typical Chinese phenotype is 20 – 30 cm long. The Indian type has a narrower shape with ridges surface. Some with miniature fruit of only 8 – 10 cm in length.

.

The bitter taste is from momordicin , which is said to have a stomachic effect

.

.

.

.









Friday, June 4, 2010

Musa x paradisiaca - nomenclature

The first scientific name given to plantain banana is Musa paradisiaca, published in 1753 by Karl Linnaeus in Species Plantarum. In 1759, Linneaus published Systema Naturae, described Musa sapientum, a desert banana.

These two names were widely used for almost 2 centuries. However, classifying bananas of S.E.Asia based on characters of plantain and desert banana are too confusing. Asia, being the center of Musa diversity, many cultivars is dual purpose.

In 1955, Simmonds and Shepherd suggested that Musa paradisiaca and Musa sapientum were hybrid cultivars, and hence recommended their abolition. They are in fact diploids and triploids that evolved through the development of sterility and partenocarpy in Musa acuminata and Musa balbisiana.

However, according to rules of International Code of Nomenclature for Cultivated Plants ( ICNCP ), hybrids can also be given scientific name, with condition the epithet must carry the prefix x to indicate hybrid nature of the species. In this case, Musa paradisiaca should be adopted as it was published ahead of Musa sapientum. Thus Musa x paradisiaca is applicable to all hybrids of Musa acuminata and Musa balbisiana.

Modern taxonomy using isozymes and molecular markers confirmed the multi-specifid origin of edible bananas. The use of nuclear or cytoplasmic RFLP probes can even determine the maternal and paternal origins of banana cultivars.


The diagrame shows interspecific hybridization of Musa acuminata and Musa balbisiana in proliferation of edible clones.