Deutscher Tropentag 2004 Berlin, October 5-7, 2004

Transcription

1 Deutsher Tropentag 2004 erlin, Otoer 5-7, 2004 Rural Poverty Redution through Researh for Development and Transformation Effets of Temperature and Grafting on the Growth and Development of Tomato Plants under Controlled Conditions Adil H. A. Adelmageed 1, Nazim Gruda 2, ernd Geyer 2 1 University of Khartoum, Department of Hortiulture, Sudan 2 Humoldt University of erlin, Institute for Hortiultural Sienes, Department of Vegetale Crops, Germany Astrat Tomato (Lyopersion esulentum Mill.) is a warm season vegetale rop with an optimum temperature for prodution of 28/22 ºC (day/night). Heat stress is a major environmental stress that limits tomato prodution during summer under arid onditions. A variety of ontrol measures and tehniques inluding ultural praties in the field have een tested previously under Sudan onditions. Grafting of heat sensitive tomato ultivars ould e used as sion, heat tolerant tomato or eggplant ultivars as rootstok to enhane heat tolerane into tomato plants. The ojetive of this study is to examine if there is any positive effet of grafting on the vegetative and reprodutive development in tomato plants under heat stress onditions. The heat tolerant tomato ultivar Summer set and the eggplant ultivar lak eauty as rootstok as well as the less heat tolerant tomato ultivar UC 82- as sion were seleted. Plants were grown under two temperature regimes 30/22 ºC and 38/27 ºC (day/night) in plant growth hamers at the Department of Vegetale Crops, Institute for Hortiultural Sienes, Faulty of Agriulture and Hortiulture, Humoldt University of erlin. The experiments were set up in a omplete randomized design with five repliates for eah treatment. The following harateristis were reorded: leaf area, fresh and dry weight of leaves and stem, fresh and dry weight of roots, numer of lusters, numer of flowers, and the numer of pollen grains per mirosopi field. In addition, hlorophyll fluoresene and eletri ondutivity were measured, suggested as a sreening tehnique for heat tolerane. Signifiant differenes were enountered etween treatment UC 82-/lak eauty and UC 82- under 38/27 C for hlorophyll fluoresene, eletrolyte leakage and some vegetative and reprodutive parameters. On the whole, grafting may have slightly positive effets on tomato vegetative growth and development under high temperature onditions. Keywords: Arid onditions, heat stress, sion, rootstok, eggplant. Introdution Tomato (Lyopersion esulentum Mill.) is one of the most important hortiultural rops in the world, and that its prodution is very onentrated in semi-arid regions (Santa-Curz et al., 2002). In the Sudan the high temperatures during summer aompanied y low humidity limit the prodution of tomato to the ooler part of the year and leads to the seasonality of the rop prodution (Adalla and Verkerk, 1968). Tomato prodution is limited y high day and night

2 temperatures (Moore and Thomas, 1952). Dinar and Rudih (1985) reported that in tomato plants, high temperatures affet several physiologial and iohemial proesses dealing finally with yield redution. Overoming heat stress prolems will have a positive impat on tomato prodution. Several reeding programmes have een made to improve the heat tolerane of tomato, ut with limited ommerial suess. One possiility to overome this prolem would e to graft the varieties onto rootstoks more effiient and apale of asoring water, nutrient and high soil temperature tolerane. Current appliations of grafting inlude most fields of plant physiology for example, to indue disease resistane aused y soil pathogens, low temperature tolerane (Ahn et al., 1999), salt tolerane (Fernandez-Garia et al., 2004), flood tolerane (Liao and Lin, 1996), drought tolerane (Iaono et al., 1998), to enhane nutrient and water uptake (Ruiz and Romero, 1999; Fernandez-Garia et al., 2002) and high temperature tolerane (Adelhafeez et al., 1975, Rivero et al., 2003a, 2003). Aording to Rivero et al., (2003a, 2003) grafting of heat sensitive tomato ultivar onto more resistant rootstok ultivars would improve plants adaptation to heat stress onditions. However, there are only a limited numer of reports on the effet of grafting on the heat stress in tomato plants. The ojetive of this study is to examine if there is any positive effet of grafting on the vegetative and reprodutive development in tomato plants under heat stress onditions. Materials and Methods The heat tolerant tomato ultivar Summer set and the eggplant ultivar lak eauty were seleted as rootstok and the less heat tolerant ultivar UC 82- as sion. They were sown in flat trays filled with standard peat mixture sustrate for germination from Gramoflor Co., Germany. Sustrate ontains aording to the produer ompany mg/l N, mg/l P 2 O 4 and mg/l K 2 O fertilizer and had ph (CaCl 2 ). The eggplant lak eauty was sown one week earlier than the two tomato ultivars. 15 days after sowing (DAS), the seedlings were transplanted into 9 m pots filled with standard peat mixture sustrate from the same ompany. The transplants were grown in the greenhouse of the Department of Vegetale Crops, Institute for Hortiultural Sienes, Humoldt University of erlin (Latitude 52 30` N, Longitude 13 25`E). Tomato plants were watered daily. Twie a week 40 ml of 0.2% solule fertilizer (12N-4P- 6K) were applied to eah pot. Twenty-two days after sowing, UC 82- was grafted onto the rootstok lak eauty and Summer set, using the pin-grafting method desried y Lee et al. (1998). Speifially, grafting erami pins were used to hold the rootstoks and sion together tightly. Plants were overed y a transparent plasti film for 7 days in order to inrease the relative humidity and to avoid dehydration y water loss. Tomato plants at 35 DAS were transferred into 14 m diameter pots filled with same sustrate. 40 DAS the transplants were divided into two sets; one set was transferred in one plant growth hamer at 30/22 C (day/night) for 13/11 h. Another set was transferred in a seond plant growth hamer at 38/27 C (day/night) for 13/11 h. On the day an irradiane of

3 550 µe m -2 s -1 from a omination of fluoresent and inandesent lights lamps were provided for eah set. The experiments were set up in a omplete randomized design with five repliates for eah treatment. Plants were randomized within the plant growth hamer every week to avoid any potential positional effets. The following parameters were reorded: Plant height (m) from sustrate surfae to the vegetative point, leaf area (m 2 ) with an eletroni leaf area meter, Type LI-COR Model 3100 (Linoln, NE-USA) with a preision ± 0.01 m 2, fresh and dry weight of leaves (g plant -1 ), as well as stem fresh and dry weight (g plant -1 ). Numer of pollen grains per mirosopi field was determined aording to experienes of our previous experiments (Adelmageed et al., 2003). In addition, eletrolyte leakage and hlorophyll fluoresene were measured, suggested as a sreening tehnique for heat tolerane. For the measurement of eletrolyte leakage, leaves grown at two temperatures regimes were exised and washed with tap water. After drying with filter paper, 2 g fresh weight of leaves were ut into small piees (aout 2 m 2 ) and plaed in flasks with 60 ml deionized water. The flasks were shaken on a rotary shaker at 26 C for 2 h (Ahn et al., 1999) and the eletrolyte leakage diffused from the leaves tissues were measured using a ondutivity meter (Digital ondutivity meter, GmH 3410, Greisinger Eletroni, Germany). Chlorophyll fluoresene was measured a portale fluorometer (PAM 2000, Walz, Co., Effeltrih, Germany). The plants were dark adapted for 30 minutes efore measurements of the hlorophyll fluoresene (Herde et al., 1999). Data analysis Colleted data were analyzed using the SPSS statistial pakage software version (Chiago, USA). One-way analysis of variane (ANOVA) was used to determine differenes among treatments. Mean separation was done y Dunan s Multiple Range Test. In tales and figures, means with same letters indiate no signifiant differenes etween treatments at a proaility level of 5%. Results and Disussion High temperature redued the vegetative growth of the different plant treatments. However, the iomass prodution of plants ome from grafting was higher than that from non-grafted plants (data not shown). Generally high temperature inreases the hlorophyll fluoresene of all treatments exept Summer set. UC 82-/lak eauty and UC 82-/Summer set had higher hlorophyll fluoresene than UC 82- at high temperature regime (38/27 C) (data not shown). Generally high temperature dereases the numer of pollen grains produed and released y all tomato treatments. The numer of pollen grains produed y UC82-/lak eauty and Summer set was higher than the numers produed y UC 82- at high temperature regime (38/27 C) (Fig. 1). UC 82-/lak eauty, UC 82-/Summer set and Summer set showed lower eletrolyte leakage ompared to UC 82- under heat stress onditions, ut no differenes were shown etween UC 82-/ Summer set and Summer set (Fig. 2).

4 80 38/27 C 30/22 C A No. of pollen grains/ mirosopi field C a C 10 0 UC 82- Summer set UC 82-/Summer set UC 82-/lakeauty Treatments Fig. 1: Effet of temperature and grafting on numer of pollen grains per mirosopi field. Differenes etween ars laeled y the same letters are not signifiant (P< 0.05) Eletrolyte leakage msm -1 g -1 fw 0,9 0,8 0,7 0,6 0,5 0,4 0,3 a A 38/27 C 30/22 C C 0,2 0,1 0 UC 82- Summer set UC 82-/Summer set UC 82-/lak eauty Treatments Fig. 2: Effet of temperature and grafting on eletrolyte leakage. Differenes etween ars laeled y the same letters are not signifiant (P< 0.05) Aording to this experiments, grafting may have slightly positive effets on vegetative growth and development of tomato produed under high temperature onditions. The results of this study are in agreement with the results of Rivero et al. (2003a, 2003) who mentioned that the effet of heat stress is muh weaker in grafted than in non-grafted plants, where diretly refleted in greater iomass prodution. Further experiments under field onditions are needed to investigate the effet of grafting on tomato plants growth and development.

5 Referenes Adalla, A.A. and Verkerk, K. (1968). Growth, flowering and fruit set of the tomato at high temperature. Neth. J. Agr. Si. 16: Adelhafeez, A.T., Harssema, H., and Verkerk, K. (1975). Effet of air temperature, soil temperature and soil moisture on growth and development of tomato itself and grafted on its own and eggplant rootstok. Sientia Hortiulturae 3: Adelmageed, A.H.A., Gruda, N. and Geyer,. (2003). Effet of high temperature and heat shok on tomato (Lyopersion esulentum Mill) genotypes under ontrolled onditions. Deutsher Tropentag 2003, Göttingen,8-10 Otoer Ahn, S.J., Im, Y.J., Chung, G.C., Cho,.H. and Suh, S.R. (1999). Physiologial responses of grafted uumer leaves and rootstok affeted y low root temperature. Sientia Hortiulturae 81: Dinar, M, and Rudih, J. (1985). Effet of heat stress on assimilate partition in tomato. Ann. ot. 56: Fernandez-Garia, N., Martinez, V., and Carvajal, M. (2004). Effet of salinity on growth, mineral omposition, and water relations of grafted tomato plants. J. Plant Nutr. Soil. Si. 167: Fernandez-Garia, N., Martinez, V., Cerda, A. and Carvajal, M. (2002). Water and nutrient uptake of grafted tomato plants grown under saline onditions. J. Plant Physiol. 159: Herde, O., Pena-Cortes, H., Fuss, H., Willmitzer, L.,and Fisahn, J. (1999). Effets of mehanial wounding, urrent appliation and heat treatment on hlorophyll fluoresene and pigment omposition in tomato plants. Physiol. Plant.: 105, Iaono, F., uella, A. and Peterlunger, E. (1998). Water stress and rootstok influene on leaf gas exhange of grafted and ungrafted grapevines. Sientia Hortiulturae 75: Lee, J.M., ang, H.J, and Ham, H.S. (1998). Grafting of vegetales. J. Japan. So. Hort. Si. 67(6): Liao, C.T., and Lin, C.H. (1996). Photosynthesti responses of grafted itter melon seedling to flood stress. Environ. Exp. ot. 36(2): Moore, E.L. and Thomas, W.O. (1952). Some effets of shading and post-hlorophenoxy aeti aid on fruitfulness of tomatoes. Proeeding of the Amerian Soiety for Hortiultural Siene.60: Riverio, R.M., Ruiz, J.M., and Romero, L. (2003). Can grafting in tomato plants strengthen resistane to thermal stress? J. Si. Food Agri. 83: Riverio, R.M., Ruiz, J.M., Sanhez, E., and Romero, L. (2003). Does grafting provide tomato plants an advantage against H 2 O 2 prodution under onditions of thermal shok? Physiol. Plant. 117: Ruiz, J.M., and Romero, L. (1999). Nitrogen effiieny and metaolism in grafted melon plants. Sientia Hortiulturae 81: Santa-Curz, A., Martinez-Rodriguez, M.M. Perez-Alfoea, F., Romero-Aranda, R., and olarin, M.C. (2002). The rootstok effet on the tomato salinity response depends on the shoot genotype. Plant Siene 162: