Aydın GÜNEŞ, Sait GEZGİN, Kadriye KALİNBACAK, Hesna OZCAN, İsmail CAKMAK

Bor elementinin bitkiler için önemi

Bitkilerde bor noksanlığı, en çok kumlu ve organik maddesi düşük olan, yıkanmanın fazla olduğu ve kireçlemenin sıklıkla yapıldığı asit topraklarda ortaya çıkar. Ayrıca, bor adsorpsiyonu/fiksasyonu yüksek olan killi ve pH’sı yüksek topraklarda da bor noksanlığına rastlanmaktadır. Bor noksanlığının ortaya çıkışıyla birlikte öncelikle hücre duvarlarının oluşumu, yapısal bütünlüğü ve işlevi zarar görmektedir. Bitkilerdeki borun yaklaşık % 90’a varan bölümü, hücre duvarlarında yapısal bir element olarak yer almakta ve biyolojik membranların stabilitesini korumaktadır. Bu özelliği ile bor, bitkinin büyüme ve verimi üzerinde ve besin elementi alımında belirleyici bir role sahiptir. Bitkilerin hücre duvarlarında pektin maddesine bağlı olarak bulunan bor, hücre duvarlarına önemli bir sağlamlık ve bütünlük kazandırmaktadır. Böylece bor bitki dokularını, patojen girişine ve enfeksiyona karşı koruyucu bir rol üstlenmekte ve bitkilerin hastalıklara karşı direncini arttıran önemli bir besin elementi olarak karşımıza çıkmaktadır. Borun en dikkat çekici işlevlerinden birisi de, polen oluşumu /tozlaşma, döllenme ve meyve tutumundaki rolüdür. Çoğunlukla, bor noksanlığı çeken bitkilerde vejetatif büyüme etkilenmezken, generatif büyümede ve meyve oluşumunda ciddi azalmalar ortaya çıkar. Bor bitki içinde floem iletim demetinde zor taşınan bir element olarak bilinir ve noksanlık belirtileri genç yapraklarda ve sürgünlerde ortaya çıkar. Bu yüzden, özellikle çiçeklenme ve meyve/tane oluşum döneminde yapraklardan bitkilere kontrollü bir bor gübrelemesinin yapılması yüksek verim için bir verimi garanti etmek adına önemlidir. Bor noksanlığı problemi, topraklarda veya yapraklarda borun yeterli olması durumunda dahi ortaya çıkabilir. Bu durum, daha çok hava neminin yüksek ve transpirasyonun düşük olduğu koşullarda belirgin biçimde ortaya çıkar. Hücre duvarı kompozisyonu ve pektin maddesi miktarına bağlı olmak üzere bitkilerin bor gereksinimi türden türe önemli farklılıklar göstermektedir. Genelde, tahıllar gibi bor gereksinimi düşük olan bitkilere 100 -200 g/da bor önerilirken; bu oran, şeker pancarı, kolza, ayçiçeği gibi bora gereksinimi yüksek olan bitkilerde 400 g’a çıkabilmektedir. Yapraktan yapılacak bor gübrelemesinde ise genelde kabul gören oran 250-300 mg B/litre olacak şekilde önerilmektedir.

Anahtar Kelimeler:

Bor, borlu gübreler, borlu gübreleme

The importance of boron for plants

In plants, boron deficiency occurs most often in acidic sandy soils with low organic matter, high leaching capacity, and frequent lime applications. In addition, boron deficiency is also observed in clayey and high pH soil with high boron adsorption/fixation capacity. Under boron deficiency conditions, the formation, structural stability and functional integrity of cell walls are damaged. Up to 90% of boron in plants is located on cell walls as a structural element and contributes to maintenance of the stability of biological membranes. With these functions boron plays decisive roles in plant growth, yield and nutrient uptake. Boron, as a cell wall element is associated with the pectin substance and provides a substantial strength and stability to cell walls. Thanks to these functions, boron plays a protective role against the penetration and infection of pathogens into plant tissues and increases high resistance of plants to diseases. One of the most particular functions of boron in plants is its role in pollination, fertilization and fruit setting. Therefore, in most cases, vegetative growth is not affected in plants by boron deficiency, while generative growth and fruit formation are affected seriously. Among plant mineral nutrients, boron show the lowest phloem mobility. For this reason, foliar boron fertilization based on leaf analysis is of great importance, especially during the periods of flowering and fruit/seed formation to ensure high yields. Boron deficiency problem can even occur in plants despite of sufficiently high amounts of boron in soils or in fully-expanded leaves which is usually common under conditions where the humidity is high and the transpiration is low. Boron requirements of plants varies considerably from species to species depending on the composition of the cell wall and the amount of pectin. Thus, it is very important to take into account plant species when boron fertilizers are applied. In general, 1 to 2 kg/ha of boron is recommended for plants with low boron requirements, such as cereals, and this rate can be 4 kg for plants with high boron requirement such as sugar beet, rape and sunflower. In the case of foliar boron fertilization, 250-300 mg B/liter is most commonly recommended rate.

Keywords:

Boron, boron fertilizers, fertilization with boron,

PDF

___

[1] Reid, R., Fitzpatrick K., Influence of leaf tolerance mechanisms and rain on boron toxicity in barley and wheat, Plant Physiol., 151, 413-420, 2009.
[2] Chen W.T., Ho S. B., Lee D. Y., Effect of pH on boron adsorption-desorption hysteresis of soils, Soil Sci., 174, 330-338, 2009.
[3] Steiner F., Lana M. C., Effect of pH on boron adsorption in some soils of Parana, Brazil, Chilean J. Agric. Res., 73, 181-186, 2013.
[4] Sarkar D., Ghosh S., Batabyal K., Mandal B., Chattopadhyay A. P., Liming effects on extractable boron in six acidic soils, Comm. Soil Sci. Plant Anal., 46, 1320-1325, 2015.
[5] Marschner P., Marschner’s Mineral Nutrition of Higher Plants, 3rd Edn. Elsevier, Academic Press, USA., 2012.
[6] Cartwright B., Tiller K. G., Zarcinas B. A., Spouncer L. R., The chemical assessment of the boron status of soils, Aust. J. Soil Res., 21, 321-332, 1983.
[7] Aitken R. L., Jeffrey A. J., Compton B. L., Evaluation of selected extractants for boron in some Queensland soils, Aust. J. Soil Res., 25, 263- 273, 1987.
[8] Sarkar D., Mandal B., Mazumdar D., Plant availability of boron in acid soils as assessed by different extractants, J. Plant Nutr. Soil Sci., 171, 249-254, 2008.
[9] Nable R. O., Banuelos G. S., Paull J. G., Boron toxicity, Plant Soil. 193, 181-198, 1997.
[10] Gupta U. C., 1979. Boron nutrition of crops: Adv Agron. Am. Soc. Agron., 31, 273-307.
[11] Cakmak I., Gezgin S, Gunes A., Kalinbacak, K., Ozcan, H., National Boron Research Enstitute-Agriculture boron research and implementation program, International Symposium on Boron in Agriculture, Ankara, Turkey, 16-18 November, 2016.
[12] Brown P. H., Bellaloui N., Wimmer M. A., Bassil E. S., Ruiz J., Hu H., Pfeffer H., Dannel, F., Romheld V., Boron in plant biology, Plant Biology., 2, 205-223, 2002.
[13] Oiwa Y., Kitayama K., Kobayashi M., Matoh T., Boron deprivation immediately causes cell death in growing roots of Arabidopsis thaliana (L.) Heynh, Soil Sci. Plant Nutr., 59, 621-627, 2013. [14] Hu H., Brown P. H., Labavitch J. H., Species variability in boron requirement is correlated with cell wall peçtin, J. Exp. Bot., 47, 227-232, 1996.
[15] Cakmak I., Römheld V., Boron deficiency-induced impairments of cellular functions in plants, Plant Soil., 193, 71-83, 1997.
[16] Blevins D. G., Lukaszewski K. M., Boron in plant structure and function, Ann. Rev. Plant Physiol Plant Mol. Biol., 49, 481-500, 1998.
[17] Davis J. M. Sanders D. C., Nelson P.V., Lengnick L., Sperry W. J., Boron improves growth, yield, quality, and nutrient content of tomato, J. Am. Soc. Hort. Sci., 128, 441-446, 2003.
[18] Cakmak I., Kurz H., Marschner H., Short-term effects of boron, germanium and high light-intensity on membrane permeability in boron deficient leaves of sunflower, Physiologia Plant., 95, 11-18, 1995.
[19] Dordas C., Brown P. H., Boron deficiency affects cell viability, phenolic leakage and oxidative burst in rose cell cultures, Plant Soil., 268, 293-301, 2005.
[20] Camacho-Cristóbal J. J., Martín-Rejano E. M., Herrera-Rodríguez M. B., Navarro-Gochicoa M. T., Rexach J., González-Fontes A., Boron deficiency inhibits root cell elongation via an ethylene/auxin/ROS-dependent pathway in Arabidopsis seedlings, J. Exp. Bot., 66, 3831-3840, 2015.
[21] Han S., Chen L. S., Jiang H. X., Smith B. R., Yang L. T., Xie C. Y., Boron deficiency decreases growth and photosynthesis, and increases starch and hexoses in leaves of citrus seedlings, J. Plant Physiol., 165, 1331-1341, 2008. [22] Sherrel C. G., Boron deficiency and response in white and red clovers and lucerne, New Zeal. J. Agric. Res., 26, 197-203, 1983.
[23] Wang Q. L., Lu L. D., Wu X. Q., Li Y. Q., Lin J. X., Boron influences pollen germination and pollen tube growth in Picea meyeri, Tree Physiol., 23, 345-351, 2003.
[24] Lordkaew S., Konsaeng S., Jongjaidee J., Dell B., Rerkasem B., Jamjod S., Variation in responses to boron in rice. Plant Soil., 363, 287-295, 2013.
[25] Bolanos L., Brewin N. J., Bonilla I., Effects of boron on Rhizobium-legume cell-surface interactions and nodule development, Plant Physiol., 110, 1249-1256, 1996.
[26] Abreu I., Cerda, M. E., de Nanclares M. P., Baena I., Lloret, J., Bonilla I., Bolanos L., Reguera M., Boron deficiency affects rhizobia cell surface polysaccharides important for suppression of plant defense mechanisms during legume recognition and for development of nitrogen-fixing symbiosis, Plant Soil., 361, 385-395, 2012. [27] Hamilton L., Reed, K. F. M., Leach E. M. A., Brockwell J., Boron deficiency in pasture based on subterranean clover (Trifolium subterraneum L.) is linked to symbiotic malfunction, Crop & Pasture Sci., 68, 1197-1212, 2017.
[28] Yu M., Shen R., Liu J., Chen, R., Xu M., Yang Y., Xiao H., Wanh H. Z, Wang H.Y., Wang C.Q., The role of root border cells in aluminum resistance of pea (Pisum sativum) grown in mist culture, J. Plant Nutr. Soil Sci., 172, 528-534, 2009.
[29] Heidarabadi M. D., Ghanati F., Fujiwara T., Interaction between boron and aluminum and their effects on phenolic metabolism of Linum usitatissimum L. roots, Plant Physiol Bioc., 49, 1377-1383, 2011.
[30] Li X. W., Liu J. Y., Fang J., Tao L., Shen R. F., Li Y. L., Xiao H. D., Feng Y. M., Wen H. X., Guan J. H., Boron supply enhances aluminum tolerance in root border cells of pea (Pisum sativum) by Interacting with Cell Wall Pectins, Front. Plant Sci., 8, DOI: 10.3389/fpls.2017.00742, 2017. [31] Lukaszewski K. M., Blevins D. G., Root growth inhibition in boron-deficient or aluminum stressed squash may be a result of impaired ascorbate metabolism, Plant Physiol., 112, 1135-1140, 1996.
[32] Krug B., Whipker B., McCall I., Frantz J., Elevated relative humidity increases the incidence of distorted growth and boron deficiency in bedding plant plugs, Hort Sci., 48, 311-313, 2013.
[33] Huang L. B., Ye Z. Q., Bell R. W., Dell B., Boron nutrition and chilling tolerance of warm climate crop species, Annal. Bot., 96, 755-767, 2005.
[34] Raisanen M., Repo T., Lehto T., Cold acclimation was partially impaired in boron deficient Norway spruce seedlings, Plant Soil., 292, 271-282, 2007.
[35] Subedi K. D., Gregory P. J., Summerfield R. J., Gooding M. J., Cold temperatures and boron deficiency caused grain set failure in spring wheat (Triticum aestivum L), Field Crops Res. 57, 277-288, 1998. [36] Cheng C. H., Rerkasem B., Effect of boron on pollen viability in wheat, Plant Soil, 155/156, 313-315, 1993.
[37] Saleem M., Yusop M. K., Ishak F., Samsuri A. W., Hafeez B., Boron fertilizers borax and colemanite application on rice and their residual effect on the following crop cycle, Soil Sci. Plant Nutr., 57, 403-410, 2011.
[38] Abat M., Degryse F., Baird R., McLaughlin M. J., Slow-release boron fertilizers: Co-granulation of boron sources with mono-ammonium phosphate (MAP), Soil Res., 53, 505-511, 2015.
[39] Brennan R. F., Bell R. W., Frost K., Risks of boron toxicity in canola and lupin by forms of boron application in acid sands of south-western, Aust. J. Plant Nutr., 38, 920-937, 2015.