Agriculture Reference
In-Depth Information
plant resistance to pathogens and pests, and enhanced adaptation to
various abiotic stresses (Upadhyaya et al. 2009 and references therein).
The major sources of variation in
uencing peanut seed composition
include those of genotype, environment, and their interaction (Layrisse
et al. 1980; Sykes and Michaels 1986; Branch et al. 1990; Grosso et al.
1994; Harch et al. 1995; Hammond et al. 1997; Upadhyaya and Nigam
1999; Dwivedi et al. 2000; Andersen and Gorbet 2002; Isleib et al. 2008;
Phan-Thien et al. 2010; Upadhyaya et al. 2012a,b). When Isleib et al.
(2008) investigated the relative contribution of these components among
the elite U.S. runner- and Virginia-type cultivars and breeding lines, they
found low genetic variation in oil (9% of the total variation), substantial
genetic variation in fatty acid composition (34
77%) and tocopherols
(42.9%), and very low genetic variation (0.5%) but high environmental
variation (68%) in sugars. More recently, Upadhyaya et al. (2012a,b), in
spite of signi
-
environment interaction (GEI) for protein,
oil, fatty acid composition, Fe, and Zn, were able to identify some
germplasm accessions from the ICRISAT peanut mini core with stable
nutritional traits. It appears that it is feasible to identify nutrient-dense
germplasm that is amenable to improvement through crop breeding.
cant genotype
×
A. Oil and Oil Quality
1. Oil Content.
Wang et al. (2009) investigated genetic variability for oil
content and fatty acid composition among 83 peanut accessions belong-
ing to two subspecies and six botanical varieties. In subspecies
hypo-
gaea
, var.
hypogaea
accessions contained signi
cantly higher amounts
of oil in the seed than did var.
hirsuta
(52%versus 47%), whereas within
subspecies
fastigiata
var.
aequatoriana
and
vulgaris
contained similar
amounts of oil in the seed (49%), not signi
cantly different from other
botanical varieties; but var.
fastigiata
contained a higher amount of oil
(50%) than var.
peruviana
(48%). Oil content among the U.S. peanut
mini core collection ranges from 43.7% to 54.2% (Wang et al. 2013),
whereas it ranges from 39.1% to 50% in the ICRISAT peanut mini core
collection (Upadhyaya et al. 2012a). Eighteen of the ICRISAT peanut
mini core accessions had 6
7% higher oil content than the controls
(mean oil 46%), with most of these accessions showing stable perform-
ance for oil
per se
and pod yield (2.2
-
2.8 t ha
1
).
The variation in oil content in 269 accessions of 20 wild
Arachis
species from six sections ranged from 45% to 55% (Upadhyaya et al.
2011b), whereas in 75
Arachis
species accessions from
-
five sections, it
ranged from 43% to 47% (Stalker et al. 1989). More recently, Huang et al.
(2012) evaluated 72 wild
Arachis
accessions representing 19 species for
