Estimation of soybean parent material for disease vulnerability

Soybean (Glycine max. (Z.) Merr.) is the main protein oil crop of modern world importance. In the South-East Asia it is known for more than 6000 years and it was used for nutritional purposes for the sake of high content of protein and fat components. It contains 14 - 15% of fat, 29 - 53% of protein and to 20% of starch [1, 2].

World experience of the advanced agriculture testifies that the most rational way of solving the protein problem is increase of soybean production, utilization of its gluten for food and also transformation of soybean protein through fodder into protein of animal origin.

The Far East is the main region of soybean production in the Russian Federation. Here there are centers of this crop selection – All Union Scientific Research Institute of soybean, Sea Scientific Research Institute of Agriculture, Far Eastern Scientific Research Institute of Agriculture. The soybean planting acreage in the Amur region in 2011 was 574 thous. ha with gross collection 843 thous. tons [3]. But in these conditions in the Far East 3/4 of the gross collection of soybean grain is produced. The main soybean seeding region is the Amur region, where 60% of its seeding is concentrated. New varieties crop productivity at State Grade Testing Establishment of the Amur region is 30 dt/ha, but regional average productivity in production remains still 12 dt/ha.

In the Amur river region yield decrease is the result of widely spread soybean diseases: Septoria and Peronospora [4]. Soybean productivity decrease also occurs as the result of its affection with numerous varmints.

Soybean productivity upside potential can be really provided for the sake of intensive technology of growth and cultivation of new disease resistant varieties and crosses. At present in soybean disease control the most rational is the package of measures where the agrotechnical method takes important place. The usage of resistant soybean varieties is the most effective protection measure that allows to apply resource saving cultivation technologies and to obtain environmentally friendly production.

Broad involvement into the hybridization new forms of the world collection immunologic potential from different cultivation regions will allow improving the soybean parent material of disease resistance.

MATERIALS AND METHODS OF RESEARCH

Experimental part of the work was done in 2009-2011 in the field conditions of the experimental field of Far East State Agricultural University. On the experimental field in natural conditions of infection the estimation of the soybean parent material for resistance to Septoria and Peronospora was carried out. The All-Russian Research Institute of Plant Industry collection of 157 varieties and varieties samples of different ecological groups with 70% dominated white-flowered types was estimated.

The disease recording was carried out in flowering period – th e be g inn in g of bean form a tio n a ccor d in g to t h e me th o d s d e v e lo p e d fo r so y b e a n s a n d o th er gra in legu m e s [5]. Dise a se progr e s s in the f ie ld co n d itio n s w a s tak e n in to co n sid era t io n applying the AllRussian Research Institute of Plant Industry scale [table 1].

Table 1 – Scale for estimation of soybeans plants prevalence w i t h d iseas es

Affection degree	Estimation			I m m u nologic f e at ur e
	By 5-point grading scale	By All-Russian Research Institute of Plant Industry index	%
very weak	1	1	1-10	Уу – hi g hl y resistant
weak	2	3	11-25	У - resistant
intermediate	3	5	26-50	С – i nter m e di ate resistant
strong	4	7	51-75	В - susceptible
very strong	5	9	75-100	Вв- st r on gly susceptible

Septoria, rustyspot Septoria glycines Т.Hemmi, agent - S e pto r ia gly cin es He mm i.: S . Sojae Syd. Et Butl. Numerous small spots (2 - 4 mm) with leaf areola are formed on the soybean leaves. Usually leaf ribs edging a spot inflate. First sp ots ar e y e l low, th e n r u s ty -brown and at last they become black-brown. At large-scale disease pr ogre ss spots fuse into entire rusty-brown spot and can occupy half and more of leaf blade (Fig.1) .

Peronospora, agent Peronospora manschurica (Naum.) Syd. P e r o no sp o r a aff ectio n particularly can be observed from the under- sid e of th e so y b ea n t e r n ate lea v e s w h e r e b lu ish -violet pannose pruinosity of fungi ascus . F r o m th e do rsa l sid e o f lea ves in the affected spaces, at first tissue is light- gr e e n b ut at th e e n d of th e v e ge tatio n p er io d it b e com e s b r o w n and gets torn. At both forms of aff e c tio n s ee d s insid e b e a n s ge t co v e r e d with easy scraped yellow-gray thick farinose consisting of fungi oospores (Fig. 2).

Figure 2. Perono spor a

Figure 1. Septoria

RESEARCH RESULTS

The varieties samples were distributed into six groups: th e E ast -Asian, the East-European, the Central- European, the North-European, the West-E ur o pe a n , the NorthAmerican, which in their turn were divided into th e gr o u p s acco r d ing to rip en e ss a n d resistance.

In a quantitave sense the variety samples of the East-A sia n g rou p – 39 types dominate. That corresponds to 28,5%. T hi s gr o up inc lud e s v a r ie ti es a n d v a r ie tie s sa m p le s of the Amur selection, the Khabarovsk Territory, Japan, K o r e a, Ch in a , Ge orgi a ( Fi g. 3 ).

According to the samples number the second place is o ccu p ie d w ith the Central and

East Europe. This ecological group includes the varieties samples of the selection of Ukrainian, Krasnodar, Saratov. Voronezh, Ryazan, Byelorussia, Moldavia, Czechia, Poland, Hungary, Bulgaria, Austria, Germany, Sweden, they correspond to 43,8 %. The West Europe is represented with the samples from France and Great Britain, they correspond to 5,8 %. Great number of samples is from The North America (19%).

о East Asia

• □    East Europe

• □    Central Europe

• □    Western Europe

• □    North America

• □    Oceania

в Africa

• □    Northern Europe

Figure 3 – Quantitative ratio according to ecological groups, %

Analysis of prevalence of varieties of different ecological-geographical origin S.glycines at epiphytotics development shows that according to the quantity the resistant samples were more than from the West- European and East-Asian group (58,5-62,5%) (table 2).

Table 2 – Sample group distribution according to resistance to S. glycines, 2009-2011

Ecological geographical group	Sample number, %
	УУ	У	С	В	ВВ
East-Asian	58,5	29,3	7,3	4,9	0
East-European	50,0	36,6	6,7	6,7	0
Central- European	20,0	53,3	10,0	16,7	0
North-European	50,0	0	50,0	0	0
West-European	62,5	37,5	0	0	0
North-American	50,0	38,5	7,7	3,8	0

Note: УУ - highly resistant, У - resistant, С - intermediate resistant, В – susceptible, ВВ – strongly susceptible.

The largest number of susceptible samples was of the Central-European origin (16,7%). In the groups of resistance to Septoria, the North-European and West-European groups, the varieties susceptible to disease are not detected.

While distributing soybean varieties along the groups of different origin resistance it is determined that each ecological geographical group scope includes both resistant and susceptible varieties. Maximum number of resistant to S.glycines varieties was marked in the Asian group. The study of varieties samples prevalence of the All-Russian Research Institute of Plant Industry collection shows that at selection of the types for hybridization is necessary to pay attention to the ecological geographical group in total but also to the diversity of its varieties with different immunological feature as well.

As the result of the investigations the tendency of increase in number of the samples resistant to S. glycines at their vegetation period increase independently from ecological geographical origin is determined. Late ripening varieties were affected with diseases less than early ripening and mid ripening varieties. In early ripening group the intermediate resistant varieties constitute from 14,3 % to 20 %, and mid ripening varieties constitute 7,1410,5 % (table 3).

The All-Russian Research Institute of Plant Industry collection includes 34 weak affected varieties and varieties samples to S.glycines from из Latvia (Vetsautses), Australia (Leslie), Canada (Maple Amder), ОТ91-3 ОАС Eclips, France (F35R/KW, Dom), Ukrainian (Kievskaya 451; Chernivetska 9; Elena), from Russia (Soer-5, Visa, Lantsetnaya, Maria, Neva, Gratsia, Seor 120-88; Seor 121-88), Hungary (NS-20, Vielnska Brunatna, Kleverhof 527), Poland (Polan), Byelorussia (Byelorusskaya 1, ДГ1, Albut, CH32-15); the USA (Zim; Balesta, Dawson); China (Nunguta 354k, КЭ-suan), Slovakia (С L CL); Czechia (ТО-1649, 1208110).

In Russia and the CIS P. manschurica is widely spread in all cultivation zones but the most harmful in the Far East South. In the conditions of the period 2009 – 2011 the disease on the soybean variety samples mostly affect seeds by the end of vegetation. It is connected with the fact that the agent is an obligatory parasite and practically soil is not a factor of contagion. Since 2005 occasionally poor weather conditions for conditional ascus formation have occurгed.

Table 3 – Sample distribution according to maturity groups, %

Ecological geographical group	Immunologic feature	Maturity group
		Early ripening	Mid- ripening	Late ripening
East-Asian	resistant	11,1	66,7	22,2
	intermediate resistant	33,3	66,7	0
	susceptible	0	100	0
East-European	resistant	23,1	57,7	19,2
	intermediate resistant	0	100	0
	susceptible	0	100	0
Central- European	resistant	50	36,3	13,6
	intermediate resistant	0	100	0
	susceptible	40	60	0
North-European	resistant	100	0	0
	intermediate resistant	100	0	0
	susceptible	0	0	0
West-European	resistant	25	62,5	12,5
	intermediate resistant	0	0	0
	susceptible	0	0	0
North-American	resistant	26,1	43,5	30,4
	intermediate resistant	50	0	50
	susceptible	0	100	0

Physiological specialization of P. manschurica evolves constant changes. Development and spreading of new aggressive races that differ by virulence take place [6]. While studying the soybean world genofond from the All-Russian Research Institute of Plant Industry collection 19 varieties and variety samples were affected with P. manschurica, more than that 31,6 % corresponds to the Amur region varieties. The samples from the USA (T6, Bernes), Germany (Gieso), Czechoslovakia (Olaszo zagi), Poland (LS-8), Russia (Dauria, Garmonia, Luch Nadezhdy) were greatly affected. The rest of the examined samples with vegetation period of 120 days and more are referred to the group of varieties resistant and highly resistant to P. manschurica.

CONCLUSIONS

• 1.    The maximum number of samples resistant to S.glycines belong to the West-European and East-Asian group (58,5-62,5%)

• 2.    The tendency of increase in number of samples resistant to S.glycines and P. manschurica at their vegetation period increase is stated.

• 3.    34 varieties and variety samples weak affected with S.glycines are defined.

• 4.    19 varieties and variety samples were affected with P. manschurica 31,6 % corresponds to the Amur region varieties. The samples from the USA (T6, Bernes), Germany (Gieso), Czechoslovakia (Olaszo zagi), Poland (LS-8), Russia (Dauria, Garmonia, Luch Nadezhdy) were greatly affected.