Browsing by Author "S.K.Vasal"

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    Nutritionally Enhanced Maize and its Importance in the Developing Countries
    (Badan Penelitian dan Pengembangan Pertanian, 2013) S.K.Vasal
    Improving nutritional quality of cereals is a noble goal as it benefits hundreds of millions of producers and consumers directly without changing their food habit. Research experience on most crops so far has been disappointing and the success stories limited.In maize, the situation is different as CIMMYT researchers were able to exploit high lysine mutants successfully to develop nutritionally enhanced maize now referred to as Quality Protein Maize (QPM). Maize being a leading crop, contributes significantly to the world’s food basket of roughly 2000 million tons every year. Unfortunately, maize has high prolamine content, and is deficient in essential amino acids lysine and tryptophan, thus making it poor in nutritional quality. Biochemists had demonstrated this fact almost hundred years ago.The discovery of high lysine mutants, opaque-2 and floury -2 by Purdue group in mid-sixties spurred enthusiasm and hope to elevate levels of lysine and tryptophan to almost double over what is encountered in normal maize.Conversion programs were initiated worldwide to obtain original soft opaque-2 versions of normal counterpart varieties and hybrids. Testing of such materials exposed a series of problems including poor agronomic performance in yield, unacceptable kernel texture, slower drying following physiological maturity and more vulnerable to ear rots and stored grain pests. As a result pessimism started growing, funding kept on declining and many institutions either completely abandoned their research work or reduced it substantially. Only in a few institutions, momentum continued as usual. Exploratory research on many different approaches was tried at CIMMYT to find a single approach or strategy that will overcome negative association of Opaque-2 gene with other undesirable traits. A combined approach of two genetic systems involving opaque-2 gene and genetic modifiers of opaque-2 locus appeared to be a viable approach. Chance events and a few other factors further enhanced confidence in this approach. A huge volume of QPM germplasm were developed which had a competitive yield performance, acceptable kernel phenotype and free from other undesirable effects.Over the past two decades or so many countries have released QPM varieties and synthetics and the trend now is to release hybrids. Some countries in recent years have released QPM single cross hybrids. Efforts are underway to develop super QPM combining high –oil and some micronutrients such as Fe, Zinc and pro-vitamin A. It is important to mention that maize is a gifted crop and has many competitive technologies which can as well be deployed in QPM research. QPM will certainly play an important role in human nutrition and to correct prevailing problems of Kwashiorkor and pellagra in some developing counties where maize is a staple food. Projected future needs for livestock and use of maize as feed holds a bright future for QPM from the standpoint of better feed ratio and reduced use of high priced supplements. These developments pose numerous challenges for future QPM research.