TITLE:
Characterization of Resistance to the Green Rice Leafhopper (Nephotettix cincticeps Uhler) in a Core Collection of Landraces in Rice (Oryza sativa L.)
AUTHORS:
Tan Van Mai, Atsushi Yoshimura, Hideshi Yasui
KEYWORDS:
Rice, Core Collection, Green Rice Leafhopper, Correlation, Germplasm
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.2,
January
22,
2017
ABSTRACT: The green rice leafhopper (GRH; Nephotettix cincticeps Uhler) is one of the most devastating insect
pests of cultivated rice (Oryza sativa L.) in temperate regions in Asia. Using the rice germplasms with biotic stress
resistance is the most effective and environmentally-friendly way to
control the insect pests in the paddy. Sixty accessions from a core set of
worldwide collection of rice were characterized for resistance to the GRH by
antibiosis test both at the seedling and at the booting stages. The positive
correlations of average nymph mortality (ANM) were observed between at the
seedling stage and at the booting stage on 3 days after infestation (DAI) (r =
0.684**), 5DAI (r = 0.680**), and 7DAI (r = 0.652**), respectively. This result
will give us the opportunity to screen resistance to the GRH with the
cost-efficient way using rice seedlings in a growth chamber. To classify the 60
accessions evaluated, the ANM of the GRH of each accession was compared to the
respective ANM of resistant and susceptible controls with the least significant
difference (LSD) value. Based on the statistical difference or similarity of
the ANMs to the resistant and the susceptible controls, we proposed the four
groups of resistance to the GRH, (I) high level of resistance, (II)
considerable level of resistance, (III) moderate level of resistance, and (IV)
susceptibility. At the seedling stage, a total of 26 accessions were highly
resistant in addition to other 6 for considerable level of resistance and other
10 for moderate level of resistance. At the booting stage, on the other hand, a
total of 18 accessions were highly resistant in addition to other 3 for
considerable level of resistance and other 5 for moderate level of resistance.
A total of 42 accessions with high to moderate level of resistance were
distributed across 16 countries in Asia in addition to each one for Madagascar
and USA. The classification of landraces based on the present protocol for
screening resistance to the insect provided fundamental information for genetics
and breeding on resistance to the GRH in rice.