Genotype and genotype x environment interaction of some rice grain qualities in Tanzania

1
Genotype and genotype x environment interaction
of some rice grain qualities in Tanzania

• Nkori J.M. Kibanda1 and
• Ashura Luzi-Kihupi2
• 1 Rice Breeder
• 2 ECARRN Coordinator

2
Genetic and Genotype x environment interaction
cont..

• Introduction
• Genotype x environmental interaction
• Is important in plant breeding programs
• When is large, testing in several (stratified)
  environments becomes necessary
• to optimize testing environments

3
Introduction cont..

• adequately measure genetic value of a cultivar
• Reports on the effect of genotype, genotype x
  environment interaction on rice grain qualities
  are available (Resurrecion, 1977, Mackill et
  al.1996, Unevehr et al, 1992)

4
Objectives

• This study had the following objectives -
• Overall objective
• Investigate the response of newly breeding rice
  genotypes and their interaction on the
  performance grain quality attributes under
  varying environments

5
Specific objectives

• Specific objectives
• To assess the contribution and the relative
  magnitudes of rice variety and variety x
  environment interaction on physical and
  biochemical traits under upland and irrigated
  ecosystems
• To estimate and assess correlations and genetic
  parameters of physical and biochemical grain
  quality attributes and determine their relative
  importance on rice improvement under upland and
  irrigated cultures

6
Materials and Methodology

• Location TAC (Ifakara) and SUA (Morogoro)
• Soil and weather data were determined
• Rice genotypes
• Collected from ARI KATRIN and SUA
• Selected based on yield potential
• Composed of conventional and mutants

7
Materials and Methodology cont..

• Genotypes SSD1, SSD3, SSD5, M15A,Line85, Line88,
  TXD275, TXD220, TXD306 and Supa (control
• Design RCBD
• Three replications with 2m x 4m
• Seeding 2-3 seeds/hill at 20cm x 20cm
• Agronomic practices

8
Materials and Methodology cont..

• Data recorded
• Grain size and shape, opacity - (Jennings et al.
  1979, IRRI 1988)
• AC - Modified simplified assay procedure (Jliano
  et al. 1981)
• GC (Campagn et al. 1973)

9
Statistical analysis

• Statistical Analysis
• Analysis of variance (ANOVA)
• Single site and combined analysis SAS software
• Estimates of variances of G, E, G x E
  interactions (AlJibouri et al. 1958)
• Estimates of Genetic Coefficient of Variation
  (Burton 1952)

10
Statistical analysis cont..

• Estimates of Heritability in the broad sense
  (Hanson et al. 1956)
• Estimates of Genetic Advance at 5 intensity
  (Johnson et al. 1955)
• Estimates of Phenotypic and genotypic correlation

11
Table 1a Performance of rice lines/variety on
physical analysis at SUA
12
Table 1b Performance of rice lines/variety on
biochemical analysis at SUA
13
Table 2a Performance of rice lines/variety on
physical analysis at TAC
14
Table 2b Performance of rice varieties/lines on
biochemical traits at TAC
15
Table 3a Performance of rice lines/variety on
physical traits combined in two locations (SUA
TAC)
16
Table 3b Performance of rice lines/variety on
biochemical traits combined in two locations (SUA
TAC)
17
Results and discussion cont..

• Genotypes were significant in all the traits
  except for grain shape in all the locations an
  when data were pooled
• Performance of genotypes on the traits varied
  across environments
• Grains ranged from very long to medium, slender
  to intermediate grain shape with small opacity

18
Table 4 Mean squares from combined analysis of
variance (ANOVA) for different physical and
biochemical characters/traits at SUA and TAC
19
Results and discussion cont..

• Location and genotype mean squares were
  significant on chalkiness, AC, GC and GT
• Genotype x Environment interactions were
  significant on AC, GC and AC

20
Table 5 Genotypic (top) and phenotypic
correlations of rice grain qualities from 10 rice
genotypes combined from SUA TAC
21
Results and discussion cont..

• Significant genotypic and phenotypic correlations
  were positive between AC with GC suggesting that
  selection for GC would simultaneously improve AC,
  but with significant negative correlation with GT
• Similar result between AC and GC have been
  reported (Juliano and Villareal, 1993)

22
Table 6 Table Variance components of grain
qualities of 10 rice genotypes at SUA and TAC
23
Results and discussion cont..

• High genetic variance were on chalkiness, GC and
  AC
• High heritability on GL, AC and GC
• High genetic advance on GC

24
Conclusion

• Grain qualities varied among genotypes and in
  varying environments
• Most lines tested meet most of the market and
  consumers preferences in Tanzania (Long to
  medium) grain size with slender to intermediate
  shape, intermediate AC, intermediate GT and soft
  GC
• GC had high heritability and genetic advance and
  had significant positive phenotypic and genotypic
  correlations with GL and AC suggesting that GC
  can be used as a reliable selection criterion for
  indirect improvement of AC in early generations
  in specific environments