Evaluation of Drought Tolerance in Winter Barley Using Different ...

Genetika, oplemenjivanje bilja i sjemenarstvo ORIGINAL SCIENTIFIC PAPER

Evaluation of Drought Tolerance in Winter Barley Using Different Screening Techniques Sorin Ciulca, Emilian Madosa, Adriana Ciulca, Giancarla Velicevici, Sabin Chis. Horticulture Faculty, Banat‟s University of Agricultural Sciences Timişoara, Calea Aradului 119, 300645 Timisoara, Romania (e-mail: [email protected])

Abstract Drought, considered as the combination of water stress plus high irradiance and temperature stresses, is the main abiotic factor limiting yield. The improvement of the yields under drought conditions therefore must combine the high yield potential and specific factors which are able to protect the crop against reduction due to this stress conditions. The objective of this study was to evaluate the drought tolerance of 23 Romanian and foreign winter barley cultivars using different screening techniques: excised leaf water loss, leaf relative water content, pollen deformation rate after osmotic stress using polyethylene glycol. Considering the appreciations of the four used techniques, the highest drought tolerance was presented by cultivars: Salemer, Secura, Compact, Adi, Dana. An pronounced sensibility for hydric stress was observed in cultivars: Precoce, Orizont, Andrei, Pfyner, Manitou. Key words: barley, drought tolerance, screening techniques.

Introduction Drought, considered as the combination of water stress plus high irradiance and temperature stresses, is the main abiotic factor limiting yield. In the east and south European environments, drought can affect the last part of the crop cycle, coinciding with grain filling. Under these circumstances, the capacity to sustain translocation of assimilates accumulated in the stem and leaves prior to anthesis to the filling grains can be a very positive trait (Araus, 2002). The improvement of the yields under drought conditions therefore must combine the high yield potential and specific factors which are able to protect the crop against reduction due to this stress conditions (Cseusz et al. 2002). Development of drought tolerant genotypes involves selection of suitable plants in segregating populations from a cross (Kumar and Sharma, 2007). Screening techniques should be fast, easy to apply, inexpensive, and capable to evaluate plant performance at a critical developmental stage in small and large populations. Several researchers (Clarke and Mc Caig, 1982; Mc Caig and Romagosa, 1989; Teulat et. al, 1997) reported that the water lose from excised leaves and leaf relative water content can be used as a screening techniques for drought resistance in breeding programs. Also, the pollen grain response after osmotic stress using polyethylene glycol (PEG) 30 and 50 % , is suitable as a routine test to select drought tolerant genotypes in breeding programs (Morgan, 1999). Material and methods The biologic material was consisted of a collection of 23 Romanian and foreign winter barley cultivars placed in experimental plots 7 m2, in three repetitions, by randomized blocks method, cultivar Dana being used as a control. The excised leaf water loss (ELWL) was tested on penultimate leaf of each selected plant from each replications, harvested from the field early in the morning. Leaf weight was taken

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immediately after sampling, dried in incubator at 28 oC at 50 % relative humidity for 6 hours and then oven dried for 24 hours at 70 oC (Clarke, 1987). ELWL(%) =[ (Fresh weight – Weight after 6h) / (Fresh weight – Dry weight)] x 100 To determine the relative water content (RWC), the harvested flag leaf was cut into 12 cm sections, and immediately weighed (FW), then sliced into 2 cm sections and floated on distilled water for 4 hours. The turgid leaf discs were then rapidly blotted to remove surface water and weighed to obtain turgid weight (TW). The leaf discs were then oven dried for 24 hours at 60 oC and dry weight (DW) was recorded. RWC was calculated by the formula (Barrs, 1968): RWC (%) = [(FW – DW) / (TW – DW)] x 100 To determine the pollen grain response after osmotic stress, three spikes of each cultivar were harvested, and dehiscing anthers in the laboratory excised. Pollen grains were being rested on two slides, after pouring a drop of polyethylene glycol solution (PEG) on each slide and putting cover slip on them, they incubated at 20 oC for 2 days. Then pollens were being screened under microscope and determine the deformation rate of them (Morgan, 1999).

Results and discussion Estimation of drought tolerance of different barley cultivars based on leaf water loss capacity is an efficient method considering the moderate heritability of this trait (Kumar and Sharma, 2007). According to this technique, the cultivars with a decreased water loss capacity manifest a high drought tolerance. Table1 Estimative values of leaf water loss and leaf relative water content in winter barley cultivars studied in Timişoara during 2005-2008. No.

Cultivar Dana Precoce Adi Mădălin Orizont Andrei Regal Compact Gerbel Manitou Esterel Majestik Lyric Plaisant Hauter Dina Ogra Salemer Landi Riniker Pfyner Secura Ulla

Excised leaf water loss (%) s% Rank 43.24+1.69 8.75 5 50.16+3.22 14.36 19 46.09+3.38 16.38 10 44.77+4.65 23.22 8 53.85+2.34 9.72 22 54.21+2.27 9.36 23 45.37+2.06 10.17 9 37.71+1.22 7.25 2 51.51+3.75 16.30 20 50.10+4.04 18.05 18 44.04+3.55 18.04 6 47.88+1.91 8.93 13 46.88+1.78 8.47 12 41.41+3.03 16.36 4 48.38+2.68 12.40 14 48.99+3.27 14.92 15 51.66+3.19 13.82 21 40.75+3.60 19.74 3 46.24+3.70 17.89 11 31.95+2.22 15.57 1 49.46+1.82 8.23 17 49.41+2.57 11.63 16 44.47+3.86 19.39 7

Relative water content (%) s% Rank 68.82+1.43 3.60 18 68.53+0.99 2.50 20 72.19+4.75 11.40 14 75.20+1.41 3.25 11 68.45+2.61 6.60 21 68.80+6.87 17.29 19 64.96+5.98 15.96 23 82.72+0.94 1.96 1 78.15+2.18 4.83 7 65.84+3.92 10.30 22 69.06+2.41 6.04 17 79.47+0.88 1.91 6 79.95+5.07 10.99 5 80.28+3.65 7.88 4 74.77+0.82 1.91 12 77.82+3.36 7.49 8 75.45+3.70 8.49 10 80.70+2.73 5.86 3 69.95+3.41 8.45 15 69.16+9.22 23.08 16 76.54+7.46 16.88 9 80.72+3.53 7.58 2 72.95+5.11 12.13 13

Exp. mean

46.46+0.47

73.93+1.22

x  sx

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x  sx

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Studied cultivars ranged between 31,95 % in cultivar Riniker and 54,21 % in cultivar Andrei, with a variation amplitude of 22,26 %, with a reduced interpopulational and a medium-low intrapopulational variability. The lowest leaf water loss values associated with a high drought tolerance was recorded in cultivars: Riniker, Compact, Salemer, Plaisant, Dana. In case of cultivars Andrei, Orizont, Ogra, Gerbel, Precoce, high values of this parameter attests a low drought tolerance. Leaf relative water content is the main parameter of water potential in hydric stress conditions. While the leaf relative water content is increasing, plant production is increasing or at least stabilizing. (Sinclair and Ludlow, 1985) This indicator presented values ranged between 64,96 % in cultivar Regal and 82,72 % in cultivar Compact, with a variation amplitude of 17,76%, with a reduced interpopulational and a reduced intrapopulational variability for most of the cultivars. A high drought tolerance correlated with high values of leaf relative water content was presented by cultivars: Compact, Secura, Salemer, Plaisant and Lyric. In case of cultivars: Regal, Manitou, Orizont, Precoce, Andrei, low values of leaf relative water content confirms a high drought sensibility. Table 2 Estimative values concerning deformation rate of the pollen grains in different PEG 6000 solutions for the winter barley cultivars studied in Timişoara during 2005-2008 No.

Cultivar

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Dana Precoce Adi Mădălin Orizont Andrei Regal Compact Gerbel Manitou Esterel Majestik Lyric Plaisant Hauter Dina Ogra Salemer Landi Riniker Pfyner Secura Ulla Exp. mean

Deformation rate PEG 6000 (30%) x  sx s% Rank 43,15+3,58 18,55 8 54,31+4,09 16,84 22 42,61+3,41 17,89 6 45,81+3,43 16,74 9 52,11+3,68 15,79 21 57,29+4,63 18,07 23 47,62+2,35 11,03 12 29,64+1,94 14,64 1 46,23+2,69 13,01 10 50,08+2,96 13,22 15 50,35+3,62 16,08 16 51,37+4,37 19,02 17 43,04+2,06 10,70 7 32,51+2,31 15,89 2 51,46+2,51 10,91 18 47,26+4,11 19,45 11 51,61+4,96 21,49 19 38,45+2,82 16,40 4 49,62+3,72 16,76 13 34,28+1,76 11,48 3 51,92+3,27 14,08 20 41,37+2,17 11,73 5 49,81+4,88 21,91 14 46,17+1,49 15,45

Deformation rate PEG 6000 (50%) x  sx s% Rank 77,97+3,85 11,04 5 89,01+5,42 13,62 22 77,75+6,11 17,57 3 79,45+4,08 11,48 8 85,83+3,48 9,07 21 94,11+6,75 16,04 23 80,87+5,38 14,88 11 81,56+6,62 18,15 12 79,75+3,91 10,96 9 83,33+7,15 19,19 15 83,64+5,37 14,36 16 84,87+5,61 14,78 17 77,92+4,03 11,56 4 79,24+5,38 15,18 7 84,99+7,86 20,68 18 80,56+6,24 17,32 10 85,18+4,61 12,10 19 77,11+5,68 16,47 1 82,83+7,93 21,41 13 78,23+5,49 15,69 6 85,58+4,88 12,75 20 77,38+6,04 17,45 2 83,03+5,71 15,38 14 82,18+0,88 5,12

Drought has a high negative impact on barley plants in flowering period affecting the plant reproductive organs, dehydration of pollen grains, their deformation and loss of viability, considerably reducing the grain production. In order to estimate drought tolerance, grain dehydration is simulated by treatment with different concentrations of polyethylene glycol. High rate of pollen grain deformation is associated with low drought tolerance, while low deformation rate indicates high drought tolerance. (Ribaut, 2006)


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As about pollen grain deformation rate in PEG 6000 (30%) solution, studied cultivars registered average values between 29,64 % in cultivar Compact and 57,29 % in cultivar Andrei, with a variation amplitude of 27,65 %, with a medium variability in cultivars and among cultivars. A high drought tolerance correlated with low pollen grain deformation rate was presented by cultivars: Compact, Plaisant, Riniker, Salemer, Secura. A high pollen grain deformation rate correlated with high drought sensibility was recorded for cultivars: Andrei, Precoce, Orizont, Pfyner, Ogra. Regarding the pollen grain deformation rate in PEG 6000 (50%) solution, studied cultivars registered average values between 77,11 % in cultivar Salemer and 94,11 % in cultivar Andrei, with a variation amplitude of 17 %, a reduced interpopulational and a medium intrapopulational variability. The lowest values of pollen grain deformation rate in PEG 6000 (50%) solution associated with high drought tolerance were observed in cultivars: Salemer, Secura, Adi, Lyric, Dana. In case of cultivars Andrei, Precoce, Orizont, Pfyner, Ogra high values of pollen grain deformation indicate a low drought resistance. Table 3 The concordance of ranks for different drought tolerance estimation techniques for winter barley cultivars studied during 2005-2008 No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Cultivar Dana Precoce Adi Mădălin Orizont Andrei Regal Compact Gerbel Manitou Esterel Majestik Lyric Plaisant Hauter Dina Ogra Salemer Landi Riniker Pfyner Secura Ulla Suma

Tech. A 5 19 10 8 22 23 9 2 20 18 6 13 12 4 14 15 21 3 11 1 17 16 7 276

Drought tolerance ranks Tech. B Tech. C 18 8 20 22 14 6 11 9 21 21 19 23 23 12 1 1 7 10 22 15 17 16 6 17 5 7 4 2 12 18 8 11 10 19 3 4 15 13 16 3 9 20 2 5 13 14 276 276

Tech. D 5 22 3 8 21 23 11 12 9 15 16 17 4 7 18 10 19 1 13 6 20 2 14 276

Ranks sum 43 127 39 61 125 124 83 33 73 106 73 69 60 29 91 63 91 19 83 56 107 33 68 1656

SSR 841 3025 1089 121 2809 2704 121 1521 1 1156 1 9 144 1849 361 81 361 2809 121 256 1225 1521 16 22142

χ2 =80.22***; χ20.1% =48.27. Technique A – Excised leaf water loss; Technique B – Leaf relative water content; Technique C –Deformation rate PEG 6000 (30%); Technique D –Deformation rate PEG 6000 (50%)

There is a high concordance between the four drought evaluation techniques, considering the very significant value χ2 =80,22***. Considering the appreciations of the four used techniques, the highest drought tolerance was presented by cultivars: Salemer, Secura, Compact, Adi,

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Dana. An pronounced sensibility for hydric stress was observed in cultivars: Precoce, Orizont, Andrei, Pfyner, Manitou.

Conclusions The lowest leaf water loss values associated with a high drought tolerance was recorded in cultivars: Riniker, Compact, Salemer, Plaisant, Dana. In case of cultivars Andrei, Orizont, Ogra, Gerbel, Precoce, high values of this parameter attests a low drought tolerance. A high drought tolerance correlated with high values of leaf relative water content was presented by cultivars: Compact, Secura, Salemer, Plaisant and Lyric. In case of cultivars: Regal, Manitou, Orizont, Precoce, Andrei, low values of leaf relative water content confirms a high drought sensibility. The lowest values of pollen grain deformation rate in PEG 6000 (50%) solution associated with high drought tolerance were observed in cultivars: Salemer, Secura, Adi, Lyric, Dana. In case of cultivars Andrei, Precoce, Orizont, Pfyner, Ogra high values of pollen grain deformation indicate a low drought resistance. Considering the appreciations of the four used techniques, the highest drought tolerance was presented by cultivars: Salemer, Secura, Compact, Adi, Dana. An pronounced sensibility for hydric stress was observed in cultivars: Precoce, Orizont, Andrei, Pfyner, Manitou. References Araus J.L., Slafer G.A., Reynolds M.P., Royo P.(2002). Plant Breeding and Drought in C3 Cereals: What Should We Breed For? Annals of Botany 89, pp. 925-940; Barrs H.D. (1968). Determination of water deficit in plant tissues. In: Kozlouski T.T. (ed), Water deficits and Plant Growth. Vol I, Academic press New-Delhi, pp. 235-268; Clarke J.M., McCaig T.N. (1982). Evaluation of techniques for screening for drought resistance in wheat. Crop Science 22, pp.503-506;. Clarke J.M. (1987). Use of physiological and morphological traits in breeding programmes to improve drought resistance of cereals. In: Srivastava et. al. (eds) Drought tolerance in winter wheat cereals. John Wiley and Sons, pp. 171-190; Cseuz L., Pauk J., Kertesz Z., Matuz J., Fonad P. (2002). Wheat breeding for tolerance to drought stress at the Cereal Research Non-Profit Company. Acta Biologica Szegediensis, Volume 46(34), p. 25-26; Kumar A., Sharma S.C. (2007). Genetics of excised leaf water loss and relative water content in bread wheat (Triticum aestivum L.). Cereal Research Communications., 35 (1), p. 43-52; Mc Caig T.N., Romagosa I. (1989). Measurement and use of excised-leaf water status in wheat. Crop Science. 29:pp.1140–1145; Morgan J.M. (1999). Pollen grain expresion of a gene controling differences in osmoregulation in wheat leaves: a simple breeding method. Australian. Journal of Agricultural Research. 50,. pp.953-962; Ribaut J.M. (2006). Drought Adaptation in Cereals. Haworth Press, Inc; Sinclair T.R., Ludlow M.M. (1985). Who taught plants thermodynamics? Then unfulfilled potential of plant water potential. Australian. Journal of Plant Physiology, 12, pp. 213-217; Teulat B., Monneveux P., Wery J., Borries C., Souyris I., Charrier A., This D. (1997). Relathionship between relative water content and growth parameters under water stress in barley. A QTL study. New Phytology, 137, pp.99-107.


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