A tribute to Damodar Dharmananda Kosambi

Scientists and students of genetics studying linkage and recombination are familiar with Kosambi’s mapping function. Chances are that they never had heard of Kosambi before. The reason - Damodar Dharmanada Kosambi was not a geneticist by training and profession, but a mathematician. He was also a statistician, historian, marxist, linguist, writer – he was everything – a multi-faceted scholar. His famous mapping function was published in 1944, in Annals of Eugenics (Kosambi, 1944). How he got into this work is not known, but Kosambi’s works generally spanned across many disciplines from mathematics to children’s literature. At the time of this publication he was teaching mathematics at Fergusson College, Pune.

Recently, Professor Kosambi’s birth centenary was celebrated, in Pune mainly by the historians and scholars. I as a student of genetics, came to know more about Kosambi after this celebrations. Ignorant of a great scientist, whose name I would have used thousands of time while doing genetic map constructions, I decided to put this tribute.

Kosambi’s mapping function estimates the recombination fraction (c) between two loci as a function of the map distance (m) between the loci, by allowing some interference, as

c = ( e^4m -1) / 2( e^4m +1)

The estimate of the map distance between two loci can be obtained from

m = ln [ (1+2c)/(1-2c) ] /4

Kosambi’s function go intermediate between actual recombination fraction taken as map distance (no interference) and Haldane’s map function (Haldane, 1919), closely predicting recombination fractions especially when the loci are linked.

Damodar Dharmanand Kosambi (D.D. Kosambi) was born at Goa on 31 July 1907 to Acharya Dharmananda Damodar Kosambi and Balabai. After his early schooling, young Kosambi moved to Cambridge, MA (USA) and studied grammer and Latin. After successful schooling at Cmbridge, he joined Harward University in 1924 studying mathematics. He discontinued his studies for a brief period and returned to India, again to join back in 1926, where he was awarded with Bachelor of Arts degree. Returning to India soon after, he joined Banaras Hindu University as a professor, teaching German and mathematics. Here he started his personal research and started publishing his findings. He got married in 1931 with Nalini, and in the same year joined Aligarh Muslim University as the professor of mathematics. He continued his mathematical research more vigorously here, and publishing his papers regularly in European languages.

Two years after he joined Fergusson College in Pune, and continued to teach mathematics. His two daughters Maya and Meera were born here. It was during this period his famous paper on mapping function was published in 1944. Kosambi had done extensive research on many areas of mathematics and published many papers. However, many of his publications went unnoticed by Indian scholars and eventually a great scientist and a historian was getting ignored to a great extend. No students of genetics were told Kosambi was an Indian scientist.

It was probably Homi J Bhabha, who recognised his talents and made him to join Tata Institute of Fundamental Research (TIFR) in 1945. He was professor of mathematics and worked there for next 17 years. During this period, Kosambi published 40 research papers, mostly on mathematics. However, his interest was shifted to history and social sciences in the later years, extensively researching on ancient Sanskrit works, numismatics and ancient history of India. Probably these later works made him to be remembered as a historian rather than a mathematician.

Kosambi authored 9 books including edited ones and 127 articles. But this number is not authentic as there are many childrens’ stories written by him. As a prolific writer, thinker, mathematical genius, linguist and historian Professor Kosambi, as Dale Riepe wrote, ‘deserves to be remembered as one of the highly gifted and versatile scientific workers and indefatigable scholars of modern India for whom a relentless search for the highest human values was the only natural way of life’.

After leaving TIFR, in 1964, Kosambi was appointed as a Scientist Emeritus of the Council of Scientific and Industrial Research (CSIR) and woked in Pune. He got involved in many historical, scientific and archaeological projects, including stories for children. But most of his works that he produced in this period could not be published during his lifetime.

Professor Kosambi died at Pune, at the age of 59, on June 29, 1966. He was posthumously decorated with the Hari Om Ashram Award by the government of India's University Grant Commission in 1980.

A biographical sketch of Prof DD Kosambi written by Chintamani Desdhmukh can be downloaded from here.

References

Haldane, J.B.S (1919) The combination of linkage values, and the calculation of distance between linked factors. Journal of Genetics, 8: 299-309.

Kosambi DD (1944) The estimation of map distance from recombination values, Annals of Eugenics, 12(3): 172-175

Gene transformation and chromosomal translocation – A plant breeder’s vista

(This was the subject of a threaded discussion at University of Nebraska-Lincoln in which I, Neway Mengistu, Nicholas Adam Crowley and Jeffery Ryan Sullivan participated.)

When a breeder is looking to incorporate “alien” genes into a line, two good choices he has are translocation and transformation (transgenic events). With a little luck, time, and effort their results can show great benefit to commercial crops. The two methods are similar because you are adding DNA segments to an existing genome without conventional breeding methods. Both of these methods are used to add a desired gene(s) to a crop which lacks the gene of interest. Chromosome translocation is caused by the interchange of parts between non-homologous chromosomes. Transgenic inserts add new, although more controllable segments, to an existing genome. The two methods require selfing and selection to be successful.

Translocation mostly gives a successful result in polyploid crops. It has been tried in wheat and rye to transfer disease resistant genes from their wild relatives. Moreover, translocation lines are more acceptable in polyploidy systems, wherein other chromosomes in the genome can compensate for a lost arm/part of chromosome eventuate in translocation events. Chromosomal translocations are random events. Translocations therefore differ from crossing over by randomness of insertion points. Any chromosomal segment can get attached to any arm of another chromosome. Classical examples are random translocations caused by transposable elements. When a chromosomal fragment carrying a desirable gene is getting translocated to a cultivated variety, the event may result in transferring of some other unknown alleles along with the gene of interest. For example, if a chromosomal segment from a wild relative carrying a disease resistance gene is translocated into a cultivated variety, it may also carry some undesirable wild traits into the cultivar. In the earlier days translocation was not much utilized in crop improvement due to this impediment. Nowadays, by use of transposable elements translocations and insertions are being utilized for site directed mutagenesis and random transfer of genetic elements.

Transformation techniques use biolistics/particle bombardment or Agrobacterium tumefaciens to insert a gene. These transformation techniques are “quick” means to introduce a gene into the plant of interest. Transformation events, try to incorporate new resistance, tolerance, or quality traits. Examples of transgene insert performed in soybean (RoundupReady® soyaben), cotton (Bt-cotton), rice (golden rice - enriched with vitamin A) etc., give a good reasoning to suggest that it can work. However, most of the traits are novel, which produce a function beneficial to humankind/cropping systems and the genes responsible are not found in that specific crop or any of its relatives. Transferring a trait using transgene insert can be manipulated by genetic engineering techniques to isolate the gene and manipulate it through cloning. In the case of a transgene, the insertion is a random event and can occur any where in the genome. This will result in hemizygosity for the transgene.

Although the advantages of these two methods are a great benefit to breeders, both have their own considerations when using them for adding desirable genes to a crop. The translocated disease resistant gene would contain surrounding chromosome segments from the wild relative. The surrounding genome would likely be undesirable since it is being donated by a distant relative to the crop. Moreover, it may take longer years to find a stable line that contain the disease resistant gene. In theory, transgenic events seem simple, and scientists/geneticists have found ways to make it as easy as it sounds, but when breeders work with translocation lines, it is hard to get everything seem simple. One case in which the breeders/scientists have used to make this technique easier is the Ph mutant in wheat. This mutation allows homoeologous pairing and crossing over between alien chromosome and its crop homoeologue, allowing transfer of chromosome segment containing the alien gene. And also if the crop is a kind of polyploid chromosomal translocation may be preferred than transgene insert - because of better tolerance of the new chromosome fragment in polyploids. On the other hand, many diseases are controlled by a single gene resistance which may not justify transfer of a chromosome fragment. A transgene insert may accomplish the job very well. However, transgene methods are still questionable by some and this must be measured when developing transgenic crops. Transgenic methods must also be isolated and sequenced for the desired gene
Notwithstanding the fact that these methods have similarities and differences, both techniques can be used for transferring desirable traits like disease resistance. The similarity between the translocation and transgene lies in the hemizygosity it produced. Since corresponding allele(s) from the translocated fragment are not found in the homologous pair, or transgene is attached only to one chromosome, hemizygosity produces a situation where only one allele is present in excess on one chromosome, while it is totally absent on its pair. As breeders, hemizygosity is not a desirable situation as we have the threat of missing the event upto 50% among gametes. The best solution is to self the plants to generate a homozygous line for the transferred gene. This homozygous line can be used for further breeding programmes. Another similarity can be from incorporation of many novel genes from translocation and transformation. Translocation between species can provide more than one beneficial gene. This is also the case in transformation; a good example is YieldGuard® plus corn hybrids. These incorporate herbicide resistance, and various insecticide genetic events to produce a corn hybrid that is beneficial to the farmer.

One way, in which these methods differ, lie in the mode of prediction of the gene transformation event itself, i.e. marker. In the case of transformation, an antibiotic resistance, herbicide tolerant or gus gene is added for easy phenotypic identification in early stages of development. In translocation crosses, phenotypic markers that may be by chance linked to the gene being transferred need to be looked to identify the plant with the alien translocation.
The major difference between a transgene insert and the translocation event is that, we know the number and nature of the genes inserted in the transgenic event, while we are unsure of the number and nature of alleles inserted through a translocation event. Shorter the translocation insert more stable will be the translocated event, while the question of stability of the transgene is still not resolved. Depending upon the length of the translocated fragments, the number of alleles will vary which may comprise of many introns and exons. Transgene insert usually has gene of interest along with antibiotic or herbicide resistance markers and/or gus markers plus the promoter regions and plasmid fractions.

When using the translocation technique in a breeding program, a breeder must consider the difficult task of achieving fertilization from the parents and possible seed abortion and using embryo rescue. In the case of transformation this is not a problem. Transformation can cause problems when the gene of interest is placed in an existing gene for interest and produces a mutant or lethal plant.

Nitrogenomics: Is the term worth science?

If anyone search the internet for the term 'nitrogenomics' chances are that you will be taken first to a page in Wikipedia (the free encyclopedia), describing,

Nitrogenomics as the branch of the study of genomics pertaining to nitrogen utilisation and assimilation in organisms. Nitrogen is a primary nutrient essential for sustaining the life of every organism. Nitrogen is freely available in the atmosphere and Earth's crust and is generally assimilated by plants and microorganisms, then moved to higher organisms through the food chain. Genomics of nitrogen assimilation lie at different levels of organisms, from microbes to higher organisms, where different genetic controls regulate the actual assimilation.

This term nitrogenomics was not available before April 2004, when I made the posting of this term for the first time in Wikipedia. The growing awareness of genomic sciences and their enormous application potential, led me to think of a specialised term for the molecular genetics and genomics of the nitrogen utilisation in the organic world. It rather amused me that the words 'nitrogen' and 'genomics' fused well. Though I coined the term without much thinking of its potential as a branch of science, I now feel that the science which is described within this term can be the science of life itself.

Nitrogen is as essential as carbon, hydrogen and oxygen in the organic world, as it forms the primary component of amino acids which makes proteins, the building and guiding blocks of organic life. But the most intriguing part of the story is that nitrogen is not freely available as in the case of other primary elements of life. In fact it is mostly available abundantly in the unavailable forms. So how then nitrogen comes into life? Its an intricate cycle that involves enormous microorganisms, entire plant kingdom and the whole animal kingdom or every living organisms in interaction with the forces of nature! The science behind this is immense.

I learned the indispensable requisiteness of this science when I started working on the genome mapping of nitrogen assimilation genes in our staple food crop, rice. By this time, more than one and a half centuries had passed since we started adding nitrogen fertilisers into agriculture. More and more nitrogen added gave more and more food grains, enabling us to feed millions of mouths that were born in the world. Indiscriminate fertiliser usage had started to take its toll through irreversible damage to the ecosystems, nitrate poisoning, eutrophication of the water bodies so on and so forth... How are we going to cope up to this situation? One way is by regulating the usage of inorganic nitrogen sources while we look for better living environment with sufficiency of food. Here we require the science I am talking of....nitrogenomics. I am convinced...are you?

Behavior of wheat awn

Recently, an interesting discussion was active in GrainGenes mailgroup, describing about an unusual behavior of wheat awn asking for further explanation on the phenomenon. The story went like this:
During a recent trip Mr Norman Rossen and colleagues met a lady who was a worker at a US Department of Agriculture facility where she did chemical research on wheat components. Mr Rossen happened to relate an experience about wheat to this lady which she never had heard and did not believe. When he was a young boy, while traveling with his dad along rural Pennsylvania they happened to stop along a wheat field. His father broke off an awn of wheat, put it on his bare, but hairy, forearm and told him to watch what happened. The head of wheat very slowly moved up his fathers arm. He recalls that the same movement repeated when they put the head of wheat on his not-quite-so-hairy arm too.
I believed this is a common phenomenon with dry awns of many grass species, especially the ones which make longer awns. I have seen kids playing with some grass species whose awns are long and 'L' shaped which spin around when they wet them. Such grass species are common in tropical South India, which is not a wheat growing region. Nevertheless the phenomenon was very similar to what Mr Norman experienced with the wheat awn.
The reason for the movement is nothing but moisture. The dry awn must be having its cells under tension because of the loss of moisture and when it absorbs water it probably must be expanding causing the movement. For the grass awns, wetting is must for the rotation. So the movement Mr Nornam observed on his dad's and his arms could have been caused by the perspiration which the wheat awns absorbed causing the movement.
Dr Maarten van Ginkel of the Plant Genetics and Genomic Division of the Primary Industries Research Victoria (PIRVic) says he has regularly demonstrated this phenomenon to interested parties using wild oats. Hold the separated seed-filled floret by the tip of the L shaped twisted awn, wet the twisted region at the base of the awn with some spittle and the floret will make a 360-degree turn in the air and sometimes more as the awn unwinds. The assumption is that lying on the ground the L-shaped tip is lodged in between some rocks or soil clods, and when the first rains set in or even excessive dew, the seed drills itself into the soil by the spring-loaded action of the trapped awn unwinding. The tips of wild oat seeds are heavily bristled forming an arrow-shaped projectile of the glumes closely adhering to the seed. Thus a handful of oat seeds (rather seeds plus fused-glumes) on the open soil one day the next morning can have fully drilled themselves into the soil, leaving no trace.
In a recently published article in Science Elbaum et al., (2007) explains the phenomenon of movement of the awns. The dispersal unit of wild wheat bears two pronounced awns that balance the unit as it falls. They discovered that the awns are also able to propel the seeds on and into the ground. The arrangement of cellulose fibrils causes bending of the awns with changes in humidity. Silicified hairs that cover the awns allow propulsion of the unit only in the direction of the seeds. This suggests that the dead tissue is analogous to a motor. Fueled by the daily humidity cycle, the awns induce the motility required for seed dispersal.

Elbaum,R., Zaltzman,L., Burgert,I., Fratzl,P. (2007) The Role of Wheat Awns in the Seed Dispersal Unit. Science 316: 884 - 886

More references:

Peart, M.H. 1979. Experiments on the biological significance of the morphology of seed dispersal units in grasses. J. Ecol. 67: 843-163.
Peart, M.H. 1981. Further experiments on the biological significance of the morphology of seed dispersal units in grasses. J. Ecol. 69:425-436.
Peart, M.H. 1984. The effects of morphology, orientation, and position of grass diaspores on seedling survival. J. Ecol. 69:425-436.

A tribute to Nikolai Ivanovich Vavilov (1887-1943)

I thought my next post should be tribute to Nikolai Ivanovich Vavilov. The great who led us to the depths of origin of cultivated species... A great warrior like Gregor Mendel, who lost to the burocarcy of science. Did he really lose?

Nikolai Ivanovich Vavilov (1887 - 1943)

Founder-Director of the Soviet Academy of Agricultural Sciences

A pioneer geneticist and the person who organised the earliest potato-collecting expeditions to the Andes after 1926, when many species and varieties were lodged in the then Horticultural Research Institute of St. Petersburg, where he and others carried out genetic analyses and field trials.
From 1920 to 1930, Vavilov organised and participated in several scientific expeditions to collect culturally important and cultivated plants from Afghanistan, Japan, China, Central and South America, Europe, North Africa, the Middle East, Ethiopia, Eritrea and Yemen. After 1938 he collected widely in the then U.S.S.R. By 1940 some 200 thousand plant species had been lodged in Russia, many sown annually in some 150 field research stations, some outside Russia.
A pioneer plant geographer, Vavilov published in 1924 a very important work The Centres of Cultivated Plant Origins - today known to biographers as "The Vavilov Centres", seven in number, and essentially the origins of most important agricultural plants. There are a few smaller centres recognised. Thus it was with great gratitude that in 1991 the writer received both membership of the then U.S.S.R. (Soviet) Academy of Agricultural Sciences and, the foundation gold Vavilov medal, a likeness of Vavilov. My own major is also in Biogeography, but the honours bestowed on me by the Academy are for my publications in Permaculture (1978 - 2000), as pioneer work on the conscious design of sustainable agricultural systems. A brief biography of Vavilov, forwarded to me by Bogdan Popov of Kiev, who was my student and interpreter for courses in Russia and elsewhere (abridged here) follows:
Vavilov was born in Moscow, his family were merchants. An elder brother was the famous physicist Sergei Ivanovich Vavilov. In 1906 Vavilov graduated from the Moscow College of Commerce, then joined the Moscow Agricultural Institute under the scientists K.A. Timiryasev, D.N. Pryanishnikov and V.R. Villiamo. At this Institute Vavilov studied in diverse disciplines, and published on the molluscan predators (snails, slugs) of plants in the Moscow province. He graduated in 1911 and worked on plant breeding, then transferred to the Bureau of Applied Botany (Director R.E. Regel) and the Laboratory of Mycology and Phytopathology (Director A.A. Yachevskiy).
From 1913 to 1914 Vavilov studied at the University of Cambridge in England under Prof. W. Bateson, and at the John Innes Horticultural Institute in London, a centre of composting research. There he published on the development of plant immunity to fungal diseases. In 1914, he went to France to study at the seed company of Vilmorin, and then to Germany ( E.Gekkel). At the outbreak of war he left Germany after great difficulty and returned to Russia, there publishing on plant immunity to viral infections.
In 1916, collecting in Fergana, Northern Iran, and the Pamirs, his material allowed him to discover the laws of homological series, hence to trace the origins of the cultivated varieties of plants. In 1917, Vavilov became Professor of Botany at the University of Saratov, but in 1921, he and colleagues moved to St. Petersberg where they set up the Horticultural Research Institute specifically intended to centre the collection of the species of cultivated plants in the world. Accessions were available for growing trials and genetic studies in the U.S.S.R. and elsewhere, but the collections have never been equalled.
In 1929 Vavilov and others founded the Lenin Academy of Sciences in Agriculture, forerunner of the U.S.S.R. Academy of Agricultural Sciences, and finally (after Glasnost) the Russian Academy of Agricultural Sciences. Vavilov was founder-president.
In the mid 1930s, Lysenko and his supporters developed a group of "Agro-biologists" who promised rapid crop improvement; their theories attracted Stalin and his secret police chief Beria, so that the "neo-Lamarkians" were in fact destroying support for Soviet genetic sciences in the scientific mode. Lysenko was able to instigate the arrest of Vavilov and his friends on 6th August, 1940, when he was collecting in the western Ukraine.
In prison, Vavilov was subjected to severe interrogations - a total duration of 1,700 hours - and was eventually sentenced to death in July 1941, later reduced to twenty years in a death cell, underground and without windows. There he contracted scurvy and developed severe dystrophy, dying on the morning of January 26th, 1943, still in Moscow. His family nearby were not told of his fate.
As a member of the Royal Society of London, he and others published The Origin, Variation, Immunity and Breeding of Cultivated Plants, translated and edited by K.S. Chester (English edition 1951).
All evidence of Vavilov's tenure at the Moscow headquarters of the Academy was removed by his fellow scientists on his arrest, and remained hidden until Stalin had died and Beria was replaced in the 1950s.
Today, Academy members (Nikinov was President in my day) speak openly and with great affection of Vavilov; Lysenko and his works are buried. The K.G.B. (then N.K.V.D.) destroyed Vavilov's manuscript A World History of Agricultural Development in 1941 as being of no value to his case!
So, a true world patriot and pioneer plant explorer was killed, aged 66 years, by jealous and vicious enemies, isolated from friends and family. He is survived by his successors and the seven hundred members of the Academy. Many scientists starved to death among the bags of grain and potatoes at the Academy in St. Petersburg during the 900-day seige by the Nazis. They died, preserving for the future the seeds of survival. We owe them all our thanks.
Vavilov died because he asserted the truth.

The Vavilov Centres
From Symons (1967) Agricultural Geography pp 11 to 12:

Vavilov listed eight independent centres of origin of the world's most important cultivated plants, based on expeditions he and other Russian scientists made throughout the world between 1916 and 1934:
1. China: The earliest and largest independent centre . . . consists of the mountainous regions of central and western China, together with the adjacent lowlands. Vavilov credited this region with important millets, buckwheat, soya beans, legumes and fruits and listed 136 endemic species.
2. India, including Burma and Assam, excluding north west India: 'India is undoubtedly the birthplace of rice, sugar cane, a large number of legumes and many tropical fruit plants, including the mango and numerous citrus plants. . .' Pulses, gourds and vegetables including cucumber, lettuce and radish were among the 117 listed species.
Also, the Indo-Malayan centre, including Indonesia and the Philippines: 55 species were listed by Vavilov.
3. Central Asia, including north west India, Afghanistan, Tadjikistan, Uzbekistan and western Tian-Shan: To this region were attributed a range of wheats, important legumes including peas, lentils and beans, and cotton. 42 species were listed.
4. The Near East, including the interior of Asia Minor, Transcaucasia, Iran and the highlands of Turkmenistan: Nine botanical species of wheat and rye, the grape, pear, cherry, fig, walnut, almond and alfalfa were among the 83 species listed.
5. The Mediterranean: home of the olive and many vegetables, was an important secondary source, in which man's part in selecting the more promising varieties for cultivation is particularly notable. 84 species were listed.
6. Ethiopia: Vavilov's expedition in 1927 established the importance of this area as an independent centre of origin, important especially for varieties of wheat, barley, sorghum and millet. 38 species were listed.
7. South Mexico and Central America (including the Antilles): Here was placed the primary centre of maize (corn), the sweet potato and upland cotton, and 49 endemic species were listed.
8. South America: The Russian expedition of 1932-1933 stressed the importance of the high mountainous area of Peru, Bolivia and part of Ecuador, remarkable for its endemic plants, notably numerous species of potato. Other centres distinguished were the island of Chiloe and the Brazilian-Paraguayan area. A total of 62 species were listed.

Major N.I.Vavilov's Expeditions

1916
Expedition to Iran (Hamadan and Khorasan) and Pamir (Shungan, Rushan and Khorog).
1921
Acquaintance trip to Canada (Ontario) and USA (New York, Pennsylvania, Maryland, Virginia, North and South Carolina, Kentucky, Indiana, Illinois, Iowa, Wisconsin, Minnesota, North and South Dakota, Wyoming, Colorado, Arizona, California, Oregon, Maine).
1924
Expedition to Afghanistan (Herat, Afghan Turkestan, Gaimag, Bamian, Hindu Kush, Badakhshan, Kafiristan, Jalalabad, Kabul, Herat, Kandahar, Baquia, Helmand, Farakh, Sehistan), accompanied by D.D. Bukinich and V.N. Lebedev.
1925
Expedition to Khoresm (Khiva, Novyi Urgench, Gurlen, Tashauz).
1926-1927
Expedition to Mediterranean countries (France, Syria, Palestine, Transjordan, Algeria, Morocco, Tunisia, Greece, Sicily, Sardinia, Cyprus and Crete, Italy, Spain, Portugal, and Egypt, where Gudzoni was explored by Vavilov's request) and to Abyssinia (Djibouti, Addis Ababa, banks of Nile, Tsana Lake), Eritrea (Massaua) and Yemen (Hodeida, Jidda, Hedjas).
1927
Exploration of mountainous regions in Wuertemberg (Bavaria, Germany).
1929
Expedition to China (Xinjiang - Kashgar, Uch-Turfan, Aksu, Kucha, Urumchi, Kulja, Yarkand, Hotan) together with M.G. Popov, then alone to Chine (Taiwan), Japan (Honshu, Kyushu and Hokkaido) and Korea.
1930
Expedition to USA (Florida, Louisiana, Arizona, Texas, California), Mexico, Guatemala and Honduras.
1932-1933
Trip to Canada (Ontario, Manitoba, Saskatchewan, Alberta, British Columbia), USA (Washington, Colorado, Montana, Kansas, Idaho, Louisiana, Arkansas, Arizona, California, Nebraska, Nevada, New Mexico, North and South Dakotas, Oklahoma, Oregon, Texas, Utah); Expedition to Cuba, Mexico (Yucatan), Ecuador (Cordilleras), Peru (Lake Titicaca, Puno Mt., Cordilleras), Bolivia (Cordilleras), Chile (Panama River). Brazil (Rio de Janeiro, Amazon), Argentina, Uruguay, Trinidad and Porto Rico.
1921-1940
Systematic explorations of the European part of Russia and the whole regions of the Caucasus and the Middle Asia.

(partially adapted from www.vir.nw.ru/history/vavilov.htm)

Why I am proud to be a Plant Breeder?

Plant breeding was the science which existed as long as the humans did... It probably started when the first man was hungry.. and when he selected what to eat... and when he probably thought to have his favourite food near his home.... He did exploration, collection and conservation of the grass and grains he needed... he grew the fruits he was fond of... He did selection of the best among the natural variability...Later, he started agriculture...and finally, selecting those types which yielded more than the one he was growing earlier.

PLANT BREEDING was continuous process...Earlier man never knew how variation occurred...and never knew how it was occurring... and how it perpetuated.

The science of GENETICS opened up a whole new area of knowledge.. the knowledge which catered the needs of ever growing global population.. The knowledge which is going to sustain the generations to come..

COME...LET US PARTAKE THAT GREAT KNOWLEDGE