Agriculture Reference
In-Depth Information
investigated in peanut. A greater understanding of the effect of global
warming on peanut quality is needed to assess its nutritional value to
humanity.
Allergy to peanuts is a burgeoning health problem worldwide. For
example,
1% of the United States population suffers from peanut
allergy (Sicherer et al. 2003). For many peanut-allergic individuals,
exposure to minute quantities of peanut can lead to severe reactions,
including anaphylaxis, which can sometimes prove fatal. To date, 12
peanut allergens have been identi
∼
ed (Chapman et al. 2007;
http://www
.allergome.org
)
, with most belonging to seed storage protein families (de
Leon et al. 2007). There is no cure to peanut allergy as it persists through
adulthood. The risk of peanut allergy, however, could be minimized by
avoiding the peanut products or by developing hypoallergenic peanuts.
This chapter is focused on developing allergen- and toxin-free peanuts
that are also nutrient dense by exploiting the natural genetic variation,
conventional breeding, and selection, and with the aid of applied
genomics, including transgene(s).
II. GENETIC VARIABILITY FOR NUTRITIONAL TRAITS
Natural variation in plant genetic resources provides the basic raw
materials for use in crop improvement programs. The Consultative
Group on International Agricultural Research (CGIAR) Consortium
gene banks hold in trust
0.6 million samples of staple food crops,
including peanut. Nearly 78% have been characterized for agronomic
traits, including resistance to abiotic and biotic stresses, while only
limited data are available on grain quality because the primary focus of
evaluation has been on morphoagronomic traits (Upadhyaya et al.
2011a). The International Crops Research Institute for the Semi-Arid
Tropics (ICRISAT) and many national programs in their gene banks hold
large collections of peanut germplasm, both cultivated and wild
Arachis
species. Core (Frankel 1984) and mini core (Upadhyaya and Ortiz 2001)
collections, which are subsets that represent substantial diversity of the
entire collection of a given species, are good resources for discovering
new sources of variation for use in crop breeding. There are various core
and mini core collections available to researchers, for example, the
ICRISAT peanut core and mini core (Upadhyaya et al. 2002, 2003);
the U.S. peanut core (Holbrook et al. 1993) and mini core (Holbrook and
Dong 2005); the U.S. Valencia peanut core (Dwivedi et al. 2008a); and the
Chinese peanut core (Jiang et al. 2008). Evaluation of these subsets led to
identi
∼
cation of new sources of variation in many agronomic traits, host
