J. Agronomy & Crop Science 177, 245—252 (1996)©1996 BlickwcH Wissenschafts - Vtrlag, BeriinISSN 0931-2250

Department of Plant Physiolog/, Polish Acadtmy ofSdencts, Kraktm', Poland; Chair of Plant Physklt^, Faculty oflre, Affiddturt Univenity ofKrahoa/, Podht:^ 3, 30-239 Krakow, PoJatui

Screening fof Drought Tolerance: Evaluation of Seed Gernunationand Seedling Growth for Drought Resistance in Legume Plants

S. GRZESLAX, W . FiLEK, G. SKRUDUK and B. NizioL

Authors' addresses: Dr S. GRZESLAK and B. NEIOL, Department of Plant Physiology, Polish Academy of Sciences,Kiakcm, Podluani 3, 30-239 Kiakow, Poland; Dt W. FiLEK and G. SKRUDUK, Chajr of Pknt Physiology, Ficulryof AgHculmie, AgricuLnire University of Kiakow, Podluiina 3, 30-239 Kratow, Poland

IFil* i lablu

RtahtdAprii 1, 1996; aaiptedjui^ 2, 1996

Abstract

Ejqietiflients were performed to evaluate seed geflninadon and seedling growth in simulated drought is screeningtechniques for drought tolerance rating. Scveia! labontoiy screening tests were evaluated for ability to estimatedrought resistance in 18 cultivars of legume plants (field bean, soybean, field pea, lupine). Drought was simulated byiwatersolutionof tnannitol of chetisical water potential ̂ ~ —0.3 and —0.6 MPa. Both solutions significantlyaffected seed germination (final gemiination and promptness index) and seedling growth parameters(seedlirig height, dry matter of shoot and root as -well as leaf injury by drou^t and high temperature).The tested cultivars could be grouped as drought resistant and drought susceptible plants. Drou^ttolerance ratings of legume plants in the laboratory tests were, on the Mrhole, consistent with the ratingst>ased on estimation of direct effects of soil drought on seed yield in field experiments. Measurementsof electroconducdvity of leaf diffiisatc to evaluate invisible injury caused by drought or liig^temperature were found to be an adequate criterion for dwughr tolerance rating. It is concluded thattolerance to drought stress in growing seedlings can be screened for by using mannitol containingnutrient solution. According to tbe results collected in this research, varieties differences in seedgemiination, seedHng growth and leaf injury affected by drought or heat temperature were evident,however, not all treatments appeared to be equally useiul for screerung of legume species cultivars.

Key words: Legume plants, screetmig test, gemiinatioii, seedling growth, kaf injury.

Introduction the vegetative growth of plants and pod filling.Seed germination and seedlii^ growth stages are

The general term 'drought tolerance' couki be sensitive to drought induced either by shortage of'^ed to refer to several types of drou^t resist- raiiiM or h i ^ ttmperature. Genotypic variabilityante such as drought escape and dehydration between and wiriiin legume species for drou^ttoietance or avoidance. Legume plants with tolerance has been reported by BOUSLAMA andrelatively high water requirements are sensitive SCHAPAUCH (1984), BROWN et aL (1985) and« very sensitive to water stress. Low rainfall level KPOGHOMOU et aL (1990). Screening for droughtduring the vegetation season is one of the most tolerance has been accomplished by selectingi environmental limitations to crop cultivars under field conditions for seed yield, but

e. Drought occurring during different this method needs a full season exfienmcnt Anof plant growth and development can limit alternative procedure may be to screen seed

«a«=SBB««: 0931-2250/96/7704-0245111.50/0

246 GRZESIAK et at

tnatctial under greenhouse conditions using seedsand yDung seedlings as a laboratory test

Techniques of screening for drought tolerance•within laige number of cultivats should be easy,rapid and inexpensive. It is aJso necessary for thelaboratory testing method to be characterized bys^nificant correlation with drought resistanceobserved in field conditions (ASHRAF and ABU-SHAKRA 1978, BLUM et al. 1989, GRZESIAK 1990).

The main methods suggested for screening fordrought tolerance in crop pknts were: seedgcnnination in osmoticwn substances (mannitol,PEG) and growth or survival of young seedlingssubjected to soil or simulated water stress andheat tctnperature stress (SULLIVAN and Ross1979).

The objectives of this study were to evaluatethe genetic variability among 18 legume cultivarssubjected to simulated drought conditions and todetertnine whether the laboratory physiologicaltests are useful criteria of screening for d r o u ^ tresistance.

Material and Methods

Plant mattfial

Eighteen culavars of legume plants (seven fieldbean, four soybean, four field pea, three lupine) werescreened for seed germination and seedliiig growthand injury by osmotieuni and heat temperaturestress. The values of the drought suscepdbiiity index(DSI) of the e:xamined varieties were calculated onthe basis of three-year-long experiments conductedunder natural conditions of plant vegetMion in theseasons 1993—1995 (GRZESIAK et al. 1996). Thetnean DSI value obtained in thrce-yeaj: fidd expeii-tnents is given in brackets along with the list of thetested cultivars. Seeds of four cultivars of the fieldbean, Bionto (0.45), Dino (0,38), Nadwisknski(0.29), Tibo (0.41). four cultivars of the soybeanAldana (0.31), Polan (0.27), Prngres (0.27), Rod(0.36), two cultivars of die field pea Mige (0.38),Miko (0.31) and three cultivars of the lupine Bac(0.38), Emir (0.44), Popiel (0.30) were obtained &omhome breeder stations, while three cultivate of thefidd bean Bourdon (0.27), Gobo (0.26), Victor(0.46) and two culdvais of the field pea Bareness(0.46), Solan (0.30) were collected from the Instituteof Agriculture Botany, Cambridge, England.

tat

Twenty seeds of each legume crop coltivars weregerminated under 0.0, -0 .3 and -0 .6 MPa, ofosmotic stress. Seeds of the tested cultivars weresurface sterilized in 70 % ethanol for 5 min, placedcai two layers of Whattnan filter paper in 13 x

18 mm Petri dishes containing 13 tnl of the appro,priate osmotic solution and incubated in an air-conditioned growth cabinet for 10 days at 25 °CDrought was simulated using water solutions ofmannitol (CJHj^Oc), a product of Lobe ChemiaM.W. 182.17. Tlie concentration of solutions at thedesired chemical water potential {)ji = -0,3 and-0.6 MPa) was calculated according to (MICHEL et il.1983), the control was distilled water {^ - 0.0 MPa).

Gertniaation was recorded when the radiclereached 5 mm in length. Counts of germinatedseeds were made each day, to compute the finalgenninadon percentage (FG) and ptamptness inda(PI), calculated as follows:

FG = ndi4 X 20" ' x 100

PI = nd2(l,0O) + ndt(0.75) + nd6(0.50)

where nd^ = number of germinated seeds by the ididay of measurement

tut

Seedlings at cotyledon stage of development weretransferred to 21 L black plastic boxes (40 x 2521 cm) where they could be grown hydroponically inan air-conditioned growth cabinet at day/nighttemperature 25/20 °C with 14 h photopcriod andrelative humidity (RH) at about 60 %. The pots werfcovered with styrophan tops having holes 0.8 cm bdiameter and spaced 2,5 cm apart. The radicle wasplaced in the hole when the seedling was trnis-pknted. The seedlings were grown in 20%HoagUnd's nutrient solution for 2 weeks of a pre-conditionir^ period. After a 14-day adaptation with-out osmoticum (0.0 MPa), stress treatments (-0.3and -0.6 MPa) were appUed for oext 14 days usingmannitol as the osmoticvun with final pH adjusted to6.5, Solutions in pocs wer« aerated throughout theduration of experiment and changed every 4—5days.

At the beginning and end of the test, tiine plantsof each treatmetit were brotight for the measure-ment of seedling height and dry matter of root milstem after drying at 60 °C for 48 h. The measure-ment results of the seedlings height and dry mattf fwere recalculated as relative indices of the growthanalysis and presented as values of the relativegrowth rate (RGR) of the seedlings height and ^matter of roots and overground parts (stern andleaves).

Stress index ^ I ) of the measured parameters wascalculated as indicated bebw:

SI = [(Treatment value) x (Control value)"'] x 100

ttst

Relative loss of interceOukr electrolytes &om !e«ftissues under drought (IDS) and heat temperatureQKT) stress wiere meiuured by the conductimenic

Sped Germinatioti and Growth and Drought Resistance 247

method of leaf injury determination. Heat tolerance(IHT) of leaf was measured accorditig to proceduredescribed by SULLIVAN and Ross (1979). Leaf discswcsc cut £iom leaves of each cultivai with 111.0 mm(field bean, soybean, field pea) or 5.2 aim (lupine)diameter cork borer. In order to detettnine IDS theissa wett excised &om three fully expanded leavessnd icuneised in test-rubes of 30 inl redistilled water(control 0.0 MPa) or 30 ml of mannitnl solutions(treatments: -0 .6 MPa) for 6, 12 and 24 h. Hightempetature stress was imposed by incubadog theleaf discs for 1 h immersed in test-tubes of 30 mlredistilled water placed in a well stirred water-bath itfour temperatujres: M ° (control), 40 °. 45 ° and 50 °C (treatments).

Initial conductance was mcasuicd after chiUing ofthe treatment solution to room temperature. Finalconductance measurements wete taken after auto-claving all tubes at 110 "C for 15 min and coolirigthetn tt> ttjoni temperature.

Index of leaf injury by d r m ^ t (IDS) and index ofhigh tcmperatutt; leaf injury Qitl) were calculatedby the follqwing formula:

IDS or IHT = 1 - [1 - (Ti X

X [1 - (Ci X "' X 100

where C and T refer to the conductivity of controlaad treatment solutions, respectively, subscript 'one'

Table 1. Gennination stress index (FG, PI) of cultivus of four legume speciesgerminated for 14 days in maimitol solutiotis at —0.3 and -O.fi MPa

speciesCultivar

Field beanBourdonBrontoDinoGoboNadwislanskiTiboVictor

SoybeanAlHana

PolanProgresRod

Field peaBarenessMigeMikoSolara

LupineBacEmirPopiel

meanrangeCVV vs DSI

Final germination

-0 .3

99.3a98.7a98.6a98.1a

100.0a99.1a98.1a

99.1a99.9a97.8a99.2a

98.6198.4a98.7a98.5a

98.6a98.7a68.2b

97.1(68.2-100.0)

7.450.15"*

-0.6

99.1a98.2a98.3a98.0a99.6a99.0a97.0a

98.9a9g.5a97-6a98.9a

98.2a98.1a98.1a98.1a

98.0a98.2a48.8b

95.6(48.8-99.6)

12.230.16'^*

Promptness indei

-0 .3

93.1bcd92.9cd92.8cd95.1a94.7a92.5d92.0d

92.6d949a944ab92.5d

92. Id92.5d92.3d941abc

92.5d9Z4d52. le

90.9(52.1-95.1)

10.710.09^

-0.6

87.9382.1b79.5c89.1188,7a75.6d65.0i

77.2d88.9a88.5a71.3e

65.1i68.4fg65.4h88.1 a

69.7ef67.1gh28, lj

74.8(28.1-89.1)

20.04-0.31'^*

Means within columns followed by the same letters arc not significandy differentat the 5 Vo level usir^ Duncan's Multiple Range Test.NS Not sigtuficant at P - 0.05.

248 GRZESIAK et al.

atid 'two' refer to initial and final cotiductance,respectively.

Statistical Miatpis

All data were analysed by standard analysis ofvariance techniques. Angular transformation wereperformed when the variable involved was expressedin relative terms. Where appropriate, Duncan'smultiple range test at the 0,05 probability level wasused to sepatate treatment means. Linear correlationanalyses were used to detetmine relationshipbetween drought susceptible index (DSI) and indicesobtained in laboratory tests.

Results and Discussion

Germination ttst

The experiments have revealed genotypic differ-ences in the response of the tested cultivars tothe conditions of simulated drougjit, measttred asthe values of the stress indes (SI) for theparameters of seed germination (FG and PI),This was observed especially in conditions ofmore severe osmotic stress, i.e. —0,6 MPa andfor the PI stress index (Table 1). In general, onthe basis of the results it can be said that the

Table 2. Seedling stress index of relative growth rate (RGR) of seedlings height (H) and dry matter (DM) ofroots and overground parts of 18 cultivate subjected to 14 days of water stress in mannitol solutions at -0.3and -0.6 MPa

SpedesCultivar

Height Roots

- 0 . 3 -0 .6 - 0 .3 -0 ,6

Stem + leaves

-0 .3 -0,6

Field beanBourdonBrontoDinoGoboNadwislanskiTiboVictor

95.3a7 9 . 1 ^

85.2cdef93,0ab

83.6defgS0,5fgh75.4h

63.8ef57,0gW58.9fgh62.1efg

59.3fgh50.4i

97. lab89.6cdef

90.7abcdef9B.la

94.6abcd90.3bcdef

87,3ef

92.6a80.3cd87. Ub91.3ab90.4ab87.2ab70.6ef

96.0ab90,6abcd89.1 abed

96.4a96,2a

91.3abcd84.3de

88,2ab77.3cd81.7abc88.6ab84.6abc80.0bc68.2de

SoybeanAldanaPolanPiogresRod

94.2ab89,3bc94.1ab93,0ab

77.4bc75.0bc79,6bc

73.5bcd

96.8abc95,2abcd

97.3ab941abcde

89.6ab85.4bc90.3ab90.7ab

92.9abc96,4a

95.1abc89.6abcd

82.7ak80,lbc88.3ab79,3bc

Fteld peaBarenessMigeMikoSolara

82.1efg90.0abc

95.3a92.0ab

52.0hi52.3hi56.8ghi65.8def

79.6g94.3abcde

86.2fg95.1 abed

64.1 f85.4bc76,3de88,6ab

80.3e93.6abc

90.3abcd93.6abc

66. le82,6ab(;79,3bc84,2iibc

LapineBacEmirPopiel

meanrange

CVV vs DSI

90.2abc90,0abc95.6a

88,8(75,4-95.6)

7.05-0.73

70.4cde70.3cde88.1a

65.2(50.4-88.1)

16.25-0.52

89,6cdef90.4bcdef96.1abcd

92.4(79.6-98,1)

5.21-0.77

79.4cd85.3bc91.3ab

84,8(64.1-92.6)

9.24-0.68

88.4bcd88.3cd95.2abc

91.5(80.3-96.4)

4.85-0.84

86,4al)C

90.3a

81,5(66,1-90.3)

7.95-0.^6

Means within columns followed by the same letters arc not significantly different at the 5 % level usingDuncan's Multiple Range TesL

Seed Germination and Growth and Drought Resistance 249

«amined varieties of field bean and soybeanwere more drought resistant when comparedwitii the fidd pea and lupine. Tihe rating of thetested cultivats with respect to their droughttolerance within the examined crop spedes waspossible on the basis of the values of the stressindex for the parameter of the promptness index(PI). Among drought resistant field bean cultivarsare Bourdon, Gobo and Nadwislanski, amongthe soybean are Polan and Progres, among thefield pea Solara and among the lupine Bac.Among the drought sensitive cultivars of field

bean we can number Victor and Tiho, among

soybean Rod, among field pea Bareness, and

among lupine Popiet TTie strongest harmfiii

influence of the drought conditions on the

parameters of seed germination when compared

with all the tested varieties was observed in the

Popiel variety of lupine.

Seedling test

Similarly as seed gertnination the seedling growth

measured by the parameters of relative growth

Table 3. Leaf tissue injury induced by simulated drought (IDS) and heat temperature (IHT) in 18 cultivars offour legume species

SpeciesCuitivar

Field b«anBourdonBrontoDinoGoboNadwislanskiTitoVictor

SoybeanAldanaPolanProgtcsRod

Field peaBarenessMigeMikoSolata

LupineBacEmirPopiel

meanrangeCVr' vs DSI

-0.3

90.1a81,led82,3cd91.7a

89.2ab81,led70.2e

79, Id89,0ab89,3ab81.4cd

80.2cd83.1cd84.2bcB«.4ab

84.2bc85.1 abc88.5ab

84,3(70.2-91,7)

6,25-0.77

Drought (IDS)

-0.6

81.6a70.6cde69.4e80.8it

80.2ab69,1 e59.0f

71.4cdeSO.ga80.8a

72.3cde

69.8e71.3cde72.4cde80.2ab

75.3bc72.1cde79.6ab

74.3(59.0-81,6)

8,19-0.84

-0.9

79,3a59.2ef61.3e

74.2abc75.4ib55.4fgh

48,6i

59-3ef73.8abc72.8bc58,6fg

49,3hi51.4hi

5 2 . 6 ^73.3abc

68,lcd65.4de71,4bcd

63,9(48.6-79.3)

15,96-0.74

Hew

40 "C

85.1 abcSO.lcd81.3cd86.8abc

84.7abcd84.8abc77.1d

81.2cd8<).3ab90.2a

83.1 abed

84,4abcd82.2bcd83.1abcd85.6abc

86.2abc83.1 abed84.2abcd

84.0(77.1-90.2)

3.74-0.64

temperature

45 °C

7O.5abc59.4e61.3e

69.2bc67.6cd6I.2e55.1f

55.2f72.4ab73.6a52.3fg

51.6%54.2f50.0g65.2d

52,2%52,lfg66.7cd

60.5(50,0-73.6)

13,26-0.69

(IHT)

50 °C

45.0cde41.le40.2e

48.4abcd44,3e41.3c40.4e

45.1bcde51.6a52.3a43.2e

44.6de44.0e42.6e

50,3abc

47,8abcd48.8ibcd49.3abcd

45.6(40,2-52,3)

8.49-0.57

M?ans within a^uttiss fallowed by the same letters are not significantly different at the 5 % level usingDuncan's Multiple Range TCSL

250 GI12ES1AK et al,

rate (RGR) of the seedling height and dry matterof roots and oveigrouiid parts was strotiglydependent on the osmotic stress (Table 2). Thtseedlings response of the culdvars to increasedconcentradoti of mannitol was the reduction oftheir increment of height, and of the dry matterof roots, leaves and stems. Ranking of thecultivars -with respect to drought tolerance was inagreement with their ranking on the basis of thegermination tests (FG and PI) except the Popielvariety of lupine which was numbered among thegroup of drought sensitive cultivais in seedgermination tests and classified among resistantin seedling growth tests.

In the group of cultivars classified as droughtresistant the observed effect of drought on therelative growth rate (RGR) of roots was lessharmful compared with the effect of drought onthe RGR of dry matter of the overground parts.

Leaf itijury test

Injury measurements of leaves exposed to simu-lated drought (IDS) or high temperature (IHI)by means of conductometHc methods haveconfirmed the inclusion of genetic variations indrought tolerance eitamined cuJtivars. A clearrating into drought resistant and drought sensi-tive groups of cultivars in DSI test was possibleafter 12 and 24 h of keeping the discs immersedin a solution of -0.6 MPa, and b IHT index afterthe discs' exposure to the temperature 45 °C(Table 3). On the basis of both tests the cultivarsBourdon, Gobo and Nadwislanski (field bean),Pofan and Progres (soybean), Solara (field pea)and Popiel (lupine) can be classified as be lo r^gto the resistant group. This is consistent with therating after seedling growth test and, except thecultivar Popid after seed germination test.

Assoaation among tests

Tables 1, 2 and 3 Ust the correlation coefficientsbetween the direct field indices of drought sus-ceptibility (DSI) and laboratory indices of tiiedrought tolerance of the tested plants. Seedlingsgrowth and leaf injury tests are significandycorrelated primarily with the indices obtained infield experiments reported by GRZESIAK et aL(1996). The absence of a significant correlationbetween the germination parameters and the DSIindex was due to the different response of thePopiel cultivar of lupine.

The statistically significant correlation coeffi-cients between leaf injury caused by drought orhigh temperature (0.51 < r > 0.81) are an \Bcation that in legume plants the mechanisms ofthe cell membrane injury were similar andindependent of the kind of the applied stressfactor. Basing on the results of the germinationand seedlings growth tests it was possible toselect cultivars differing in their drought tolance which may be of use both in agriculturalpractice and physiobgical investigations.

The evaluation of the plant tolerance tovarious abiotic stress factors have been used tostudy the response of plants to unfavorablevegetation conditions. Under field conditions,tests for drought tolerance within large segttgating population are expensive and recjuire fullseason data from a few years long experiments.Alternatively methods of laboratory evaluation ofplant tolerance to various stress factors may besimpler and more convenient in use. Attemptswere also made to make use of physiological testsin plant breeding to select genotypes differing intheir tolerance to various environmental stresses.Plant breeders are looking for efficient physiolo-gical laboratory tests which might be applied inthe ptxjcesses of selection; and one of therequirements of the breeders is the possibilityof conducting these tests on young seedlings.The last postulate presents some problems ftonitiie physiological point of view as the phase ofvegetative growth is less sensitive to drought incomparison with the subsequent developmentstages (WRIGHT 1971, RICHARDS 1978).

Tests most firequently used for drougjitresistance estimation are seed germination, seed-ling growth and leaf injury affected by simulateddrought or high temperatures (GATES 1964,KASSAM 1972, KmzEK 1985, BLUM ct al. 1989).The experiments here presented have shown thatboth for the phase of germination and that ofinitial seedling growth it is possible by means ofsimple and easy tests to predict the responses ofvarieties exposed to water deficit in an externalenvironment. Based on the test results it ispossible to divide the varieties examined intogroups differing in their drou^t tolerance.

This division has proved in general to beconsistent in all applied tests, except the Popi«lcultivar of lupine, whose reaction to drougiitduring seed germination and seedling growth w»scompletely different, "nierc may be variousphysiological reasons for the observed responseof this variety which require fiirdter investi*

Seed Gennination and Gro^Pth and Drought Resistance 251

gations. They may be connected with thedisturbance of the process of dry seed imbibitionand injuries of embryo cells, or they tnay dependon the utilization of seed reserves after initialictivation of enzyme system.

At the germination phase the water content isof significant importance m the activation ofenzymes respotisible for embryo developtnentand utilization of endosperm. At the early stageof seedling growth, after the first leaf has beenformed, hydradon of cells is responsible for theintensity of photosynthesis and d:ie processes ofcell growth (GATES 1964, WRIGHT 1971, BLUM etal. 1980),

Observations made dtiHng these experimentsindicate also the appearance of after-effects ofdrought on the germination progress. In tnanycases it has been observed that the seedsgcttninating in conditions of osmotic stress didnot continue the growth of radiqle and shootaftdr they had been transferred to the controlconditions (results not shown).

The correlation coefficient between diedrought susceptibility index (DSI) obtained infield condition (GRZESIAK et al, 1996) and theindexes of stress parameters noted for laboratorytests was high and significant. The significantcorrelations between drougjit and heat stressnoted in this study have been observed insotghum and soybean, but not for com andwheat (TRAPANI and GENTTNETTA 1984, MARTI-NiEoo and LoRENZONr 1985). It suggests that themechanistns of cell membrane injury due to soil>nd atmospheric drought may be physiologicallydifferent.

According to the results collected in thisresearch, varieties differences in seed germi-nation, seedling growth and leaf injury affeaedoy drought or heat temperature were evident,however, not all treatments appeared to beequally usefiil for screening of legume spedesiti

Auslese fur Troclsoheitstoleram: Samenkei*mung und SamlingswachBtuin im Hiitblick^uf Ttockenhettstcfiistenz bei Leguniinoaen

Es wmden Untersuchungen durchgefiihrt, um°^ Samenkeimung und das Samlingswachstumbei sanulicrter Trockenheit als Auslesetechnik furTmckenheitstoleranz zu vemrenden, Zahlreiche-aboratoriumstests wurden ausgewertet um die

Trockenheitsresistenz von 18 Kultivaren vonLeguminosen (Ackerbohnen, Sojabohnen, Erbse,Lupine) zu bestinnmen. Die Diirrc wurde durcheine Losung von Mannitol mit einem chemischenWasserpotential ^ = - 0 3 und -0,6 MpaerzeugL Beide Losungen beeinfluflten signifikantdie Samenkeimung (Keimungsprozente und Kei-mungsschneliigkeit) sowie das Samlingswachs-tum unter Beriicksichtigung der Samlirigshohe,Trockenmasse der Triebe und Wurzeln sowieBlattschadea ais Folge der Dtirre und hoherTemperatur. Die Kuldvare konnten in einetockcnheitsresistente und tockenheitsempfind-liche Gruppe eingeordnet werden. Die Trocken-heitstoleranz der Legurtiinosen in den Labora-toriumsuntereuchungen waren grundsatzlich inUbcrcinstitnmung mit den Befunden aufgnmdvon Bodentrockenheit und deren Atiswirkungenauf den Samenertrag in FekJexperimenten. Mes-sur^en der Konduktivitat von Blattdiffusateti zurAuswertung nicht sichtbarer Schaden als Folgeder Trockenheit oder hoher Temperatur erwiesensich als ein geeignetes Kriterium der Bestimmungder Trockenheitstoleranz. Es wird angenammen,dali auf Trockenheitstolefan2 heranwachsenderSamlinge unter Veiwendung der Manitolmethodein NShrlosungen ausgelesen werden kann. UnterZugrundelegung der Ergebnisse dieser Unter-suchung cigaben sich Sortenunterschiede in derSamenkeimung, dem Samlingswachstum tind beiBlattschaden, die durch Trockenheit oder Hitze-temperaturen veruisacht wurden; allerdings nichtalle Behandlungen erschienen gleichctmaflen fiircine Auslese der Sorten von Leguminosermrtengeeignet.

Ackno«dedgement

"niis research was supported by the State Committee ofScientific Investigarion (KBN), grant No, 5 S301 03604. The authors express their gratitude to Dr RICHARDSD. FENWICK of Institute of Agricultural Botany, Cam-bridge, England, for the seeds of field bean aod field peathey supplied free of chaige needed in the experiments.We would like to thitik Dr AGNBS DE BARBARO for herhelpful conunents on the niaouscript.

References

ASHRAF, C. M., and ABU-SHAKRA, 1978: Wheat seedgermination under low temperature and moistuKstress, Agton, J. 70, 135—139.

BLUM, A., B. SINMENA, and O. Zrv, 1980; An evaluation•f seed and seedling d ro i^ t eolcruice screening testsin wheat. Euphyticft 29, 727—736.

252 GRZESIAK et al

BuJM, A,, G, GOLAN, J. MAYER, B . SINNMENA, I*

SHPitER, andj, BuitHA, 1989: The drought tesponst oflandraces of wheat from aorthem Negev Desert inIsrael Euphidca 43, 87—96,

BOUSLAMA, M., and W. T, SCHAPAUCH, 1984i Stresstolerance in soybean. 1. Evsduadon of free screeningtechniques for heat and diought tolerance. Crop Sci.24, 933—937.

BROWN, E, A., C. E. CAVINESS, and D . A. BROWN, 1985:

Response of selected soybean cultivars to soilmoisture deficit. Agton. J. 77, 21A—278.

GATES, C. T,, 1964: The effects of water stress on plantgrowth. J. Aust. Inst, Agr. Sci. 30, 3—22.

GKZESIAK, S,, 1990: Reacdon to drought of inbreds andhybrids of maize {Zsa mays L.) as evaluated field andgreenhouse expeiiments. Maydica 35, 303—311.

GEIZESIAK, S., W, FILEK, S. PIENKOWSKI, and B, NiziOL,

1996: Scteening for drought resistance: Evaluation ofdrought susceptibility index of legume plants innatural growth conditions, J. Agr. and Crop Sci. 177,237—244.

KASSAM, A. H. , 1972: Determination of water potentiiiland tissue characteristics of leaves of Vida faba L,HortRes. 12, 12—23.

KPOGHOMOL'. B . K. , V. T. SAPRA, and C. A. BEYI, 1990;

Screening for drought tolerance: Soybean genninationand its relationship to seedling response. J. Agron.Crop Sci. 164, 153—159.

KRIIEK, D . T . , 1985: Methods of inducing water sttessin plants. Hon. Sd. 20,1028—1038.

MARTTNILIJO, P. , and C. LORENZONI, 1985: Response of

maize genotypes to drought tolerance tests. Maydica30,, 361—370,

MicHB-, B. E,, K, O, WIGGINS, and W. R J. OITTLOW,

1983: A guide to establishing water potential foiaqueous two phase solutions (Polyethylene glycol plusdextian) by amendment with mannitoL Plant Physiol.72,60—65,

RICHARDS, R. A,, 1978: Variation between and withinspecies of rapeseed (Brmsia campestris and B, m^Hi) in

response to drought stress. HI. Phjrsiologicd andbiochemistry characters. AusL J. Agric. Res. 29,495—501.

SuLUVAN, Ch. Y., and W. N. Ross, 1979: SelecBng fordrought and heat resistance in grain sotghum. In: H.MUSSEL and R. STAPLES (eds.). Stress physiology incrop plant, pp. 263—281, J, Wiiey and Sons, NwYork.

TRAPANI, N . , »nd E. GENTtNETTA, 1984: Screetiiog ofmaize genotypes using d m u ^ t tolerance tests.Maydica 29, 89—100.

WRIGHT, L.N,, 1971: Drought influence on germinatianand seedling emergence. In: K. L. LARSON and J, D.EASTIN (eds.). Drought injury and resistance in crops,pp. 19—44, Spec. Pub. no. 2. Crop Sd, Soc. Am.Madison, Wl.