(go
to KOMUGI Home) (go
to WIS List) (go
to NO.73 Contents)
Wheat Information
Service
Number 73: 5-7 (1991)
Identification
of souces of resistance against flag smut (Urocystis agropyri
(Preuss) Schroet) of wheat
G. C. Bhatnagar, S. N. Mali and V. K. Bhatnagar
Wheat Improvement Project, Agriculture Research Station,
Durgapura, Jaipur - 302 018, India
Hitherto the flag smut of wheat caused by Urocystis agropyri
(Preuss) Schroet was considered to be of minor importance in the
country. However, in recent past it has been reported in damaging
proportions from many parts of the country. The disease was first
reported in 1906 by Butler from Layalpur (Punjab) and its sporadic
reports are on record from to time. The disease has now become one of
the yield reducing factors in Uttar Pradesh, Punjab, Haryana, Delhi,
Himachal Pradesh, Rajasthan and Madhya Pradesh. Even some of the
present day cultivars have developed susceptibility and the incidence
of the disease has been on increase in these states (Butler 1918;
Mundkur 1944; Rao 1952; Bedi 1957; Kothari and Dange 1968; Sethi and
Singh 1971 and Bhatnagar and Vijaylaxmi 1975). The situation with
respect to Flag smut incidence in Rajasthan during the past five
years is more alarming as the losses to the extent of 40-60% have
been reported from different parts of the state (Bhatnagar et al
1978). Besides, studies on loss estimation, control through cultural
practices and chemicals, studies on varietal susceptibility and
screening of promising breeding material at different stages of its
development were conducted to identify resistant donars so as to make
wheat breeding programme more meaningful.
Materials and Methods
A sick plot (2500 m2) was developed at Agricultural
Research Station, Durgapura. The inoculum load in the sick plot was
so much that the susceptible varieties exhibited 100% infection. The
topography of the infected area was uniform. However, additional
inoculum was supplemented through seed and soil at the time of sowing
to put maximum selection pressure of the pathogen. Each cultivar was
planted in 2 m rows at 5 cm depth with three controls (Lal Bahadur,
HD 2009 and D-134) of highly susceptible varieties after every tenth
row. The planted material was grown under normal optimum conditions
of fertility, irrigation and other cultural practices recommended for
wheat crop in this agro-climatic zone. The incidence of flag smut was
recorded on individual plants at flag leaf stage, and per cent
infection was calculated by formula:
(Number of infected
plants / Total number of plants)
X 100
Besides the available commercial varieties, the entries in plant
pathological screening nursery including IET and U. R. T material
were subjected to testing. The cultivars or varieties exhibiting less
than one per cent infection have been categorised as resistant.
-->Next
(go
to KOMUGI Home) (go
to WIS List) (go
to NO.73 Contents)