Russia

 

Barley Breeding for Disease  Resistance  in the North Caucasus

 

Shevtsov V., N. V. Serkin, T. E. Kuznetsova,  Chanda D.,

V. N. Suprunenko, Gerasimova A. I., Levshtanov S. A.

 

Krasnodar  Lukyanenko Research Institute of Agriculture

KNIISH, Krasnodar, 350012, Russia, e-mail: vshevtsov@inbox.ru

 

Disease infection is one of the most important biotic constraints, limiting barley productivity especially in high yielding environments with fertile soils and annual precipitation more than 400 mm. In the North Caucasus the most common diseases are net blotch (Pyrenophora teres), root rot (Fusarium graminiarum), snow mold  ( Fusarium nevale), scald (Rhynchosporium secalis),  leaf rust of barley (Puccinia hordei), powdery mildew (Erysiphe graminis), loose smut  (Ustilago nuda), covered smut (Ustilago hordei), barley yellow dwarf virus, barley  stripe mosaic virus and other leaf and head diseases. The economic importance  of every disease varies from season to season. The priority depends on weather conditions, the list of recommended varieties, genetic structure of cultivated varieties. In the Krasnodar Research Institute of Agriculture the main direction in  barley improvement for disease resistance is increasing of field or general tolerance.  Though our pathologists  have their own conception, emphasizing on high resistance to every pathogen, we can put some historical facts, approving our approach.  A spring barley  variety Uzniy was cultivated on millions hectares and was the most spread in the former Soviet Union in spite of its very high susceptibility to powdery mildew. Some years ago a French variety Ager, very susceptible to many leaf diseases and loose smut, has been released in the In the North Caucasus and occupied dominant areas under winter barley  in the region.  The variety could compensate losses in productivity by high resistance to lodging and optimal plant architecture. The new variety Lokus, developed with the use of Ager,  was always affected by many leaf diseases. It  could not meet formal requirements of the official trials, concerning the acceptable level of resistance Therefore,  the State Variety Testing Committ5ee  refused to  include Lokus into the Recommended List. Finally, it was released because farmers widely cultivated the new variety thanks to  its earliness and good cold tolerance.  During  the last decades leaf rust has become the most important biotic constraint  for winter barley  in the North Caucasus.  The local check varieties Kozir and Michailo turned out to be severely  affected (table 1). 

 

Table 1. Winter barley performance in advanced  trials.  Krasnodar

 

Variety	1990		1994
	Susceptibility to leaf rust, %	Yield, t/ha	Susceptibility to leaf rust, %	Yield, t/ha
Kozir	10	7.60	85	7.56
Michailo	10	8.26	80	7.92
Secret	5	7.42	5	7.46
LSD 0.05		0.38		0.36

 

All three varieties are released in the region and they were developed at the same time. The main criteria for selection was stable performance and high yield.

Two statements could be concluded from the data: either leaf rust is not very serious pathogen limiting barley productivity or the released varieties Kozir and Michailo possess compensation mechanism facilitating their good performance even under wide spreading and  high severity of  leaf rust.  Therefore, it would be mistaken to use disease resistance as the main criteria for selection in yield trials. The final decision should  be concentrated on the good combination of economically important characters including disease tolerance.

 

In  the last two seasons with heavy rains and snow falls  during winter period snow mold (Fusarium nevale)  became the most important constraint, which decreased considerably yield potential of some lines especially susceptible to this new pathogen.  Very high positive correlation was observed between resistance to snow mold and winter barley productivity in yield trials.  A new line with lax six row head has been identified in the advanced yield trials as a promising variety Fakir due to its high resistance to the disease (table 2).

 

Table 2. Characteristics of the new winter barley variety Fakir.

Krasnodar Research Institute of Agriculture

 

 

• Resistance, score: 1-very low,  5- medium, 9-very high

 

The new variety has evident superiority in cold tolerance and resistance to snow mold but its straw is not strong enough for cultivation on fertile soils in central part of the region. The yield trials, carried out in the Northern zone  of Krasnodar region,  showed very good adaptation of the variety to local environments  (table 3).

 

Table 3 Performance of the new winter barley variety Fakir in the  North-Kuban experimental station

 

Variety	Cold tolerance, %*	Yield after preceding crops, t/ha
		W.  wheat	Sunflower	Average	%
Dobrinya	30.6	5.29	8.78	7.04	100
Michailo	11.6	6.06	8.88	7.47	104
Fakir	66.7	7.38	8.91	8.14	114
LSD	9.8	0.35	0.42

 

• Cold tolerance – percent of survived plants after artificial freezing

 

Thus, the new variety Fakir is especially suitable for low yielding conditions. Some additional research is needed to find out optimal technological requirements for its cultivation.