PROBLEMS OF CARYOPSIS AND STABILITY OF WINTER AND SPRING FORMS OF CEREALS TO PHYTOPATHOGENIC FUNGI OF GENUS FUSARIUM LINK - Ecological Consequences of Increasing Crop Productivity - page 101

spp. (8.8%); Mucor spp. was found in 7.6 percent of seeds; fungi of the genus Penicil-
lium spp. were not detected.
The study revealed differences in morphometric characteristics of seeds. The seeds
grown at the experimental plot in the city of Tyumen formed seedlings with more
developed primary root system (the length and number of roots) and coleoptile (L)
compared with the seeds of Yekaterinburg. No signifi cant differences were found in
the length of shoots and the mass of roots and shoots.
In our experiment conducted in the laboratory on four cultivars of soft spring
wheat, we observed the dependence of the ability of seeds to normal germination on
their contamination by pathogens. Cultivar Tyumenskaya 80 had the lowest laboratory
germination of seeds among cultivars—88.2 percent at the maximal level of infection.
In less contaminated cultivars (Saratovskaya 57, Comet, Mir 11), seed germination
ability was higher:—98.5, 99.0, and 99.3 percent for Mir 11, Comet, and Saratovskaya
57, respectively.
Fungi of Fusarium genus are the most common pathogens among soil infections.
They cause disease of roots and root collar, which leads to the death of productive
stems, and the empty spike of infested plants.
According to the percentage of seedlings affected by the disease, cultivars Com-
et, Tyumenskaya 80, and Mir 11 were classifi ed as middle susceptible ( P b = 28.15-
30.45%, 21.59-28.43%, and 20.40-29.50%, respectively), and cultivar «Saratovskaya
57» as low susceptible ( P b = 12.48-18.48%) (Table 11.2).

TABLE 11.2 Evaluation of spring wheat samples on infectious background for resistance to

Fusarium spp.

Phytopathological
analysis of seeds

Benzimidazole
method

The rots of root Sum

of de-
grees
of
dam-
age

P b
(%)

Degree of
damage

Р b
(%)

Degree of
damage

Р b
(%)

De-
gree of
dam-
age

Cultivar

Tyumenskaya
80

21.59 2 24.00 4 25.55 2 8

Comet 28.15 1 35.43 1 21.87 3 5

Saratovskaya
57

18.48 4 34.35 2 21.11 4 10

Mir 11 20.40 3 24.27 3 28.89 1 7

Note : > 40 percent—susceptible, 20-40 percent—middle susceptible, and 10-20 percent—low
susceptible.

A stronger root growth and inhibition of vegetative parts were observed in the
study of morphometric parameters on the background of the infected seedlings (Table
11.3).