Some features of tillering in different wheat species.
Olga A. Yevdokimova.
We examined the great variation in tillering among
Triticum L species. The number and condition of tiller
buds in the seed germ; general tillering energy; tillering productivity;
and the contribution of tillers to grain yield were evaluated.
During a 3-year period, the wheat cultivars Saratovskaya 29 (T.
aestivum L.), Kharkovskaya 46 (T. durum Desf.), and
K-417 (T. dicoccum Schuebl.) were investigated under field
conditions. The same number of tiller buds was discovered in germs
of seeds of all investigated varieties (Table 6). Buds in the
two first nodes represent the apex and profillum, and buds in
the other nodes represent undifferentiated tuberous roots.
Table 6. Tiller development in different wheat species (average for 2 years)
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General Productive Contribution of tiller
Species tillering tillering shoots to grain yield, %
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T. aestivum 2.67 ± 0.33 1.32 ± 0.01 16.0 ± 0.45
T. durum 3.08 ± 0.33 1.31 ± 0.04 16.4 ± 1.20
T. dicoccum 3.48 ± 0.09 1.99 ± 0.03 43.3 ± 5.50
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Table 6 indicates that emmer wheat sharply exceeds
durum and common (bread) wheat for these traits. Differences between
T. aestivum and T. durum in productive tillering
and tiller contribution to grain yield were not discovered. However,
durum wheat exceeds common (bread) wheat in general tillering
ability. The most clear differences were in the survival of productive
tillers.
The ratio of productive tillers to the general amount
of germinated tillers was 14 % for T. aestivum, 10 % for
T. durum, and 40 % for T. dicoccum.
Laboratory of Genetics and Cytology
Agricultural Research Institute for South-East Regions, Tulaikov
St. 7, Saratov, 410020 Russia.
V.A. Krupnov, S.N. Sibikeev, S.A. Voronina, and V.M. Semenov.
The effect of the prolamine locus on yield and grain protein content of red spring bread wheat.
Near-isogenic sibs with high and normal grain protein
content (GPC) were selected from the backcross population `Saratovskaya
29*7/Atlas 66'. The influence of the prolamine locus on
agronomic traits of isolines in field trials was studied. Experiments
were conducted from 1989 to 1993 at the Central Research Field
near Saratov in south Chernozem. The plots were not fertilized.
All sowings were on summer fallow in early May, and all harvests
were in early August. Sowing rates were 4 million seeds per ha.
Each experiment was grown in a randomized complete block with
four replications. Results indicate that line 894 had a higher
GPC, from 0.79 to 2.68 % (average 1.51 %), than line 874, and
these differences were significant for all years. In these lines,
the culm length, date of anthesis, test weight, harvest index,
1,000-kernel weight, and grain yield were not significantly different,
with the exception of 1990, when under a severe leaf rust epidemic
the grain yield of line 894 was significantly higher. The lysine,
methionine, and threonine contents were slightly higher in the
flour from line 894 than in flour from line 874. The alveograph
volume, loaf volume, and texture score were similar among sibs.
Genetic control of flour color in bread wheat and wheat/Agropyron lines.
The genes Lr19 (Sharma and Knott 1966), Lr19d
(Marais 1990), and LrAgi1 and LrAgi2 are known to
be linked closely to yellow flour pigment. However, there are
few reports on the genetic control of flour color in lines with
Agropyron translocations. In our investigations, an analysis
of segregation in hybrids between bread wheat cultivars with white
and cream-colored flour, `Saratovskaya 46' and `Saratovskaya
29', respectively, and wheat-Agropyron lines with yellow
flour, Ps 29 (Lr19), Agro 139 (LrAgi1), and Agro
58 (Agri2), allowed us to determine that the trait of flour
color is controlled by two groups of genes. The first group of
genes is derived from bread wheat and durum wheat and the second
from Ag. elongatum or Ag. intermedium. The
genes for flour color have partial dominance and additive effects.
The genotypic formulas for the cultivars and the wheat-Agropyron
lines are:
Saratovskaya 46 Yf1 yf2 yf3 yf4 white flour
Saratovskaya 29 yf1 Yf2 Yf3 yf4 cream flour
Agro 58 yf1 Yf2 yf3 YfAgi1 yellow flour
Agro 139 yf1 Yf2 yf3 YiAgi1 yellow flour
P8 29 yf1 Yf2 Yf3 YfAge1 yellow flour
where Yf1 was derived from bread wheat, Yf2
and Yf3 were derived from durum wheat, and YfAgi1
and YfAge1 were derived from Ag.intermedium
and Ag. elongatum, respectively.
References.
Sharma D and Knott DR. 1966. Can J. Genet Cytol 8:137-143.
Marais GF. 1990. Plant Breed 104:152-159.
The discovery of pathotypes of P. recondita
that are virulent to Lr19, Lr19d, LrAgi1,
LrAgi2, and Lr38 has made it possible to combine
in one genotype these genes and others that are not overcome by
leaf rust race pp19. We had determined previously that race pp19
was not virulent on genes Lr9, Lr23, Lr24,
and Lr26. However, later experiments showed that the gene
combinations Lr19/Lr9, Lr19/Lr23,
and Lr19/Lr24 are thermosensitive. Moreover, an
effect of the genotype that was the donor of Lr19 was detected.
For example, the hybrid `L 504/TC Lr24' and
other hybrids (L 546, L 583, and L 2032) with the cultivar `Thatcher'
(Lr24) differ from each other by reaction to pp19 at 18_C
and 30_C The hybrid F1 of the crosses `L 504/TC Lr9'
and `L 1089/TC Lr9' differ from each other
only at 18_C. Comparing the hybrids `L 1089/TC Lr23'
(Lr19/Lr23), `L 1089/TC Lr26'
(Lr19/Lr26), and `L 1089/Seri 82 (Lr19/Lr23
+ Lr26), the influence of the Lr26 gene was determined.
Under different temperatures, the Lr gene combinations `Lr19/Lr23
+ Lr26' displayed the same infection type to race
pp19 as Lr19/Lr26. In our experiments, the combination
of Lr19/Lr26 produced infection type = 0 (resistant)
in all hybrids at 18_C and 30_C. Thus, the gene combinations of
Lr19/Lr9, Lr19/Lr23, Lr19/Lr24,
and Lr19/Lr26 provide resistance to the pp19 pathotype,
although thermosensitivity and genotype dependence on expression
of the Lr genes were detected.
The study of Lr19 gene frequency in doubled haploid populations of bread wheat.
Yu. E. Sibikeeva.
The frequency of the Lr19 gene in hybrid F2s
and DH populations was studied in the following combinations:
`L 503/S 55', `L 504/S58', and `ATS
7/L 1063'. The parental lines L 503, L 504, and L1063 have
Lr19, and S 55, S 58, and ATS 7 are susceptible to leaf
rust. Gene segregation in the F2 generation fit the theoretically
expected ratio of 3R:1S. This fact shows that, in these combinations,
the transmission of Lr19 was not induced by the Sd1
gene. In hybrids `L 503/S 55', `L 504/S 58',
and `ATS 7/L 1063', the action of Sd1, which
is closely linked to Lr19, is suppressed.
In DH0 populations of these combinations, the ratio
of resistant to susceptible lines does not fit the expected ratio
of 1R:1S, and an excess of resistant lines was found. In the DH1
and DH3 generations, an increase in the number of susceptible
lines was observed. The offspring of some regenerants had a different
reaction to leaf rust during the DH0-DH3 generations from
0; to 3+. This variation was observed until the DH3. In DH3 populations
of `L 503/S55' and `ATS 7/L 1063', the
ratio of resistant to susceptible lines fit the 1R:1S ratio, but
in the `L 504/S 58' population, an excess of susceptible
plants were observed. On the DH line, heterozygosity for Lr19
was observed in a DH3 population of `AST 7/L 1063'.
This line was derived from callus.
The incorportation of a solid stem in durum wheat breeding in the Volga Region.
V.A. Elesin and A.A. V'Yushkov.
Damage to bread and durum wheats by the sawfly (Cephus
pugmaeus L.) in the Volga Regions is observed in some years.
During 1992-94, durum wheat lines with solid stems were
evaluated.
Analogous lines (AL) were produced by the backcross
method of Dr. V. Yushokov in Samara, ARI (P. Bezenchuk). The durum
wheat cultivar Bezenchukaya 139 (B139) was used as the recipient
parent and durum wheat lines UM-6001 (Canada) and k-50989 (Russia)
were used as donors of the solid stem trait.
The Als were studied in yield trials, in 4-row plots
(8 sq m) with two (1992) and four (1992-94) replications.
The comparison of ALs with solid and normal stems indicates that
the ALs with solid stems did not differ from their sibs and recipient
parent for number of ears per sq. M, height, heading date, resistance
to lodging, and grain yield. At the same time, the solidness indicies
were 4.1-4.9 for ALs with solid stems, 2.3-2.7 for
its sibs, and 2.3 for the recipient parent.
Thus, the ALs of the durum wheat cultivar B 139 with
solid stems are prospective donors of this trait to protect against
sawfly damage and also may impart drought resistance to new cultivars
for the Volga Region.