Sorghum Diseases in India

Table 2. Mean threshed grain mold rating (TGMR) 1 Table 2. Mean threshed grain mold rating (TGMR) , and physical characteristics of grains of four
groups of advanced sorghum breeding lines, parental lines, and improved controls evaluated at
ICRISAT Center rainy season 1985.
1 Table 2. Mean threshed grain mold rating (TGMR) , and physical characteristics of grains of four
groups of advanced sorghum breeding lines, parental lines, and improved controls evaluated at
ICRISAT Center rainy season 1985.
1 , and physical characteristics of grains of four
groups of advanced sorghum breeding lines, parental lines, and improved controls evaluated at
ICRISAT Center rainy season 1985.
Type of Lines Pericarp
3
Floaters (%)
Dehulling
recovery Tannin Flavanselection
(no.) color Testa 2 TGMR A B (%) 4
(cat.eq) 5 4-ol
GM-resistant 2 Brown + 2.3 52 56 75 1.53 3.19
GM-resistant 7 Red - 2.3 23 29 84 0.12 4.57
GM-resistant 5 White - •2.2 21 27 87 0.11 0.16
GM-susoeptible 7 White - 5.0 63 76 64 0.25 0.01
GM-susceptible 2 White - 5.0 78 87 56 0.10 0.00
GM-resistant Brown/
(parental lines) 3 Red +/- 2.4 52 49 70 2.27 5.44
GM-susceptible
(controls) 5 White - 5.0 73 86 60 0.11 0.01
SE - - - ±0.15 ±5.7 ±3.8 ±2.3 ±0.10 ±0.16
1. TGMR = Threshed grain mold rating on a 1 to 5 scale, where 1 = no mold, and 5 = 50% grain surface area
molded.
2. Testa present (+); testa absent (-).
3. Floater A = grains of a sample (%) that floated when submersed in a solution of NaNO3 NaNO3 NaNO3 NaNO3 NaNO3 NaNO3 NaNO3 NaNO3 (1.3 specific gravity).
Floater B = grains in a sample (%) that floated in a 1.327 specific gravity solution of tetrachloro-ethylene and
odorless kerosene.
4. Percentage of whole grains recovered after dehulling.
5. Cat.eq = Catechin equivalent.
50% flowering, plant height, plant color, panicle
type, absence or presence of the testa layer, and
grain mold resistance. We also determined grain
density (% floaters Of each F2 segregate derived
from three crosses (IS 14384 x ICSV 1, IS 14384 x
SPV 104, and IS SPV 104 x IS 14385) and the
tannin content of each F2 segregate derived from
one cross (IS 14384 x SPV 104). Frequency distribution
plots of mold resistance of F2 segregates
derived from IS 14384 x ICSV 1 and IS 14384 x
SPV 104 crosses are shown in Figures 2 and 3,
respectively; that of floaters (%) of similar
crosses in Figures 4 and 5, respectively.
Correlation coefficients between mold resistance
and plant and grain traits were determined
to identify plant or grain traits significantly
associated with mold resistance. In a few
crosses, mold resistance and time to 50% flowering
were significantly correlated, indicating that
late-flowering F2 segregates in these crosses tended
to escape mold damage. For the majority
of crosses/ however, correlation coefficients between
mold resistance and time to 50% flowering
278
were small and not significant. Also correlation
coefficients between panicle type and mold resistance
were low and insignificant except in one
cross (IS 14384 x SPV 104), indicating that openpanicle
types are not always associated with
mold resistance. We observed several F2 segregates
with open-panicle types severely molded.
Correlation coefficients between mold resistance
and floaters (%) and tannin are presented
in Table 3. Mold resistance was highly correlated
with floaters in all crosses except among browngrained
F2 segregates derived from IS 14384 x
ICSV 1. This confirms a previous observation
(Glueck and Rooney 1980) that grain hardness is
associated with mold resistance. Tannin content
was highly correlated with mold resistance
among brown-grained F2 segregates, confirming
the observations of Harris and Burns (1970) that
sorghum genotypes with high-tannin content
resist grain molding. Correlation coefficients
between TGMR and floaters (%), dehulling recovery
(%), tannin and flavan-4-ol levels among
white- and red-grained mold-resistant ad-