Rice Genomics and Genetics 2015, Vol.6, No.1, 1-5
2
Figure 2
Dendrogram (NTSYS-PC) displaying diversity
among 94 HKR47
×
MAS26 F
2
plants and parental
genotypes using allelic diversity data at 125 SSR loci
Figure 3
Two dimensional PCA scaling displaying diversity
among 94 F
2
plants (HKR47
×
MAS26) and parental
genotypes using allelic diversity data at 125 SSR loci
respectively. It has been reported that a cultivar
having more root number, high fresh and dry root
can explore more soil volume for effective
absorption of water (Amudha et al., 2009). Results
also revealed that deep roots are associated with
water stress tolerance in aerobic rice. Several
research groups have reported identification of
markers linked to the genes/QTL for root traits such
as maximum root length, basal root thickness, dry
root weight, total root weight and their potential role
in water use efficiency or drought tolerance (Price et
al., 1997; Yadav et al. 1997; Li et al. 2005; Toorchi
et al., 2007; Liu et al. 2008; Qu et al., 2008).
Kato et al. (2010) studied root response to aerobic
conditions in rice and observed that total root length
under aerobic and near-saturated conditions was
10%~30% of that under flooding. Matsuo et al.
(2009) reported that root number, fresh and dry root
were higher in Sensho (upland variety) compared to
Koshihikar (lowland variety) in hydroponic culture.
Martin et al. (2007) reported that the rice varieties
(ADT 39 and PMK 3) that were suitable for
cultivation under aerobic conditions had longer and
deeper root system compared to the other rice
varieties. Increased root length allows roots to
penetrate hard pans characteristic of some lowlands,
thickness and density improves water uptake by
producing more and larger root branches (Ingram et
al., 1994). The improvement of upland rice through
a deeper root system is thought by many to be a
promising way to increase water uptake, and
ultimately grain yield, under water stress conditions
(Fukai and Cooper, 1995).
