Journal of Nature Studies 9(2)/10(1): 47-52 ISSN: 1655-3179
GENETIC VARIATION AND AGRONOMIC TRAITS ASSOCIATED WITH NITROGEN USE EFFICIENCY IN MAIZE Makhziah Rahman and Yonny Koentjoro Department of Plant Breeding and Agronomy of Agricultural Faculty of University of Pembangunan Nasional Veteran East Java, Indonesia Corresponding author: [email protected]
Abstract - Nitrogen use efficiency (NUE) should become a good consideration in order to minimize the negative impacts of excessive N fertilizer, particularly on crops that need lots of nitrogen (N) such as maize (Zea mays L.). Therefore, to identify the efficient genotypes in utilizing N that useful for maize breeding program, this study was carried out. The objectives of this study were to identify genetic variation and agronomic traits related to NUE in maize. Four maize genotypes (Pioneer-11, Bisma, Arjuna and Madura local) were planted on four different N fertilization regimes (0, 60, 120, 180 kg N/Ha). Statistically significant interaction between genotypes and N rates were observed on grain weight, kernel number, a thousand of grain weight, N uptake, N uptake efficiency and N utilization efficiency. There were positive correlations between grain yield and both N uptake efficiency and N utilization efficiency, and between root system (root length, root number and root dry weight) and N uptake efficiency. Bisma had a greater grain yield in all of N rates and more adaptive to N decrease than others, wherein decreasing of N rates from 180 kg N/Ha to 120 kg N/Ha and 60 kg N/Ha was not different significantly in grain weight per plant and kernel size (a thousand grain weight). Decreasing of N rates from 180 kg N/Ha to 120 kg N/Ha and 60 kg N/Ha decreased grain yield respectively 1,13% and 4,21% in Bisma. It seemed that genotypes were higher yield showed higher NUE. Bisma is considered as the most efficient genotype among others, whereas Madura local is the least N efficient genotype. Keywords: Nitrogen use efficiency, genetic variation, agronomic trait, maize INTRODUCTION Maize (Zea mays L.) is one of the most important crops all around the world and is the second crop after rice is widely cultivated in Indonesia. For supporting growth and high yield, corn needs a lot of nitrogen 160 – 190 kg N/Ha (350-420 kg urea ha) (Akil and Dahlan, 2008), but nowadays N fertilizer has over used and is reached 230-322 kg N/ha (500 – 700 kg urea/ha) in Indonesia. The use of N fertilizer in maize crop is estimated to reach 5 million tons per year in developed countries and more than 5 million tons in developing countries (FAO, 2005). Farmers usually use more inorganic fertilizer than organic fertilizers, whereas in the long term it can cause damage to agricultural land due to soil structure has changed and the balance of nutrients is disrupted. In addition, due to excessive N fertilization can cause nitrate pollution because only about 33% of N uptaken by plants while the rest is lost due to leaching, volatization, run off and denitrification (Raun and Johnson, 1999, Frink et al.,1999). In an effort to reduce negative impacts on the environment and reduce N fertilizer it should be considerable to use N fertilizer more efficiently or improving Nitrogen Use
Efficiency. Besides cultivation, N use efficiency was also determined by genetic. Interactions between environment and genetic expected are able to increase N use efficiency. Jeuffroy et al., (2002) suggested that three main groups of tools are already available to help farmers to attain the new conflicting goals: (1) diagnostic tools, which can be used to characterize crop N nutrition status at a given date or stage, making it possible to correct N deficiencies; (2) genotypes, with characteristics more or less adapted to the aims of the farmers (high yield anduor high quality); (3) crop models, that allow the consequences of cultural practices on yield, quality and environment losses to be simulated. Improved understanding of crop production systems in relation to N-supply has come from a knowledge of basic plant biochemistry and physiology. Gene expression leads to protein synthesis and the formation of metabolic systems; the ensuing metabolism determines the capacity for growth, development and yield production, this constitutes the genetic potential (Lawlor, 2002). Development of varieties will be more efficient if the process of physiological and genetic basic is known and well understood (Gallais and Hirel, 2004). Genotypes selection based on mechanism
To cite this paper Makhziah Rahman, M. and Y. Koentjoro. 2011. Genetic variation and agronomic traits associated with nitrogen use efficiency in maize. Journal of Nature Studies.9(2)/10(1): 47-52.
Rahman and Koentjoro
more efficient in N uptake and metabolism is a strategy to increase the N utilization. For that understanding of the biochemical and physiological processes on N uptake and N assimilation in plants is needed. It is also associated with the genetic potential that is manifested by the yield potential. This understanding is very important for characterization of plant which is used as basic for screening maize genotypes are more adaptive to the low N input. In order to develope maize low-N tolerant maize genotypes, it is necessary to characterize maize plant that use N efficiently. Characterization of phenotype is also very important for identifying genes control traits associated with N use efficiency through Quantitative Trait Loci (QTL) that can be used as Marker Assisted Selection (MAS) for developing low-N tolerant maize genotypes. Hence this study was carried out to find out the genotypic variation and agronomic traits associated with nitrogen use efficiency. MATERIAL AND METHOD Field experiment at the farmer’s field in Menganti district, Gresik East Java Indonesia was carried out on March – July 2010 to determining NUE and agronomic traits in four maize cultivars (hybrid and open pollinated): Pioneer, Bisma, Arjuna and Madura local were planted at 0 Kg N/Ha, 60 kg N/ha, 120 kg N/ha and 180 kg N/ha was repeated three times in split plot randomized block design. The N rates was allocated to the main plots, whereas genotypes distributed to the subplot.Two maize seed of uniform size were planted per hole and later thinned to one at two weeks after planting in single row, 6 m long, 0.6 m apart and 0,20 within row, there were six rows each plot. The site had a mean annual rainfall of 2000 mm and the soil can be described as Aluvial. N soil was 0.23% analyzed 3 days before planting. N fertilizer as urea was applicated in two times, 2/3 part at three weeks after planting and 1/3 part at anthesis. Phosphate and Potassium fertilizers applicated 100 kg P/ha and 100 kg K/ha before sowing. N analysed by Kjeldahl method. Data were recorded 25 days after silking for N uptake and at harvesting. N uptake is the product bimass x N-content. Nitrogen use efficiency was analysed according to two main components of NUE model formulated by Moll et al.(1982): - N uptake efficiency = ratio of total plant to N supply per unit area = plant N /(soil N+ N fetilizer) Journal of Nature Studies. 9(2)/10(1)
- N utilization efficiency (Nutl) = ratio of grain weight per plant N= grain weight/plant N Statistical analysis used was analysis of variance, least significant difference test and correlation analysis with SPSS version 17. RESULTS AND DISCUSSION Genetic Variation in Agronomic Traits: Nitrogen fertilization strongly influence on growth and yield of plant, as well as maize is highly responsive to N fertilizer. To minimize excessive use of N fertilizer that could harm environment, it is necessary to find the low-N tolerant maize genotype. Yield are often used as the main parameter to determine level of crop tolerance to environmental stress that in this case a low-N stress. How much yield decrease due to the reduction of N fertilizer that still can be tolerated. There were interaction between genotypes and N rates in grain weight, kernel number and 1000 grain weight. The highest grain weight was attained by Bisma for N treatment, and the least was Madura local. Three genotypes Bisma, Pioneer and Arjuna yielded grain weight were not different significantly when N fertilizer rate reduced from 180 kg N/ha to 120 and 60 Kg N/Ha, whereas Madura local strongly influenced N reduction caused grain weight decrease (Table 1). Low N fertilization caused yield reduction but according to Banziger et al., (1997), genotype is tolerant to low N fertilization if yield reduction does not exceed 43%, while Gallais and Coque (2005) suggest that when the plant material performs relatively well under low N input, it should be selected under N deficiency conditions for which yield reduction does not exceed 35–40%. Grain weight decrease due to reduction of N fertilization rate for the Pioneer-11, Bisma and Arjuna less than 40% except Madura local was greatest yield reduction more than 40%. Reduction of N treatment from 180 kg/ha to 120 kg N/ha, 60 kg N/ha and 0 kg N/ha kg/ha caused grain weight decrease respectively 4.5%, 13.70%, 18.83% in Pioneer-11; 1.13%, 4.21%, 34.27% in Bisma;; 2.24%, 5.38%, 14.38% in Arjuna, and 4.6%, 10,09%, 50.46% in Madura local (Fig. 1), therefore Bisma had least grain weight decreasing was caused by reduction of N fertilization rate, Pioneer and Arjuna also relatively little reduction compared to Madura local has declined greatest. Difference of yield among genotypes tested at each fertilizer N rate showed that Bisma was the highest yield in all N fertilizer
Genetic variation and agronomic traits associated with nitrogen use efficiency in maize
rates (Fig.2). The biggest yield difference was between Bisma and Madura local, while the smallest difference attained between Bisma and Pioneer-11 in all of N rates. Reduction of N fertilizer rates caused decrease kernel number in all cultivars except Madura local (Table 1). Bisma was the least decrease in kernel number and Madura local was not affected by reduction of N fertilizer rate but it had the least kernel number in all N fertilizer rates. Reduction of N rate 180 kg N/Ha to 60 kg N/Ha reduced kernel number significantly in Bisma, but not significant in Pioneer-11, Arjuna and Madura local. Gallais and Hirel (2004) reported, among the yield components, kernel number was the most affected (32%) while kernel weight was reduced by only 9% decline in yield due to the reduction of N caused by ovule abortion (ovaries) after fertilization. Ovule abortion can also caused the limited product of photosynthesis that affect growth at vegetative and after flowering (McCullough et al., 1994). Such abortion could be the result of a limitation in the source of photosynthetic products, which also affects post-anthesis growth (29% reduction) much more than vegetative development (14% reduction), as already shown by McCullough et al., (1994). This suggests that, just after fertilization, the sink demand must be too high compared with the availability of resources, thus leading to embryo abortion in a genotype-dependent manner.
N rate reduction caused grain size (a thousand grain weight) decrease in Arjuna and Bisma significantly, but not in Pioneer-11 and local Madura (Table1). The largest seed was attained by Pioneer, then Bisma, Arjuna and the smallest seed was Madura local. Genetic Variation In Nitrogen Use Efficiency Another parameter used to determine lowN tolerant genotype is nitrogen use efficiency (NUE). Two main components of NUE are N uptake efficiency and N utilization Efficiency (Moll et al., 1982). N uptake is N content of biomass (N content x biomass). N uptake represent the capacity of plant to absorb nitrogen. Pioneer-11 had the highest N content at high N fertilization (180 KgN/ha), but decreased significantly when N rate reduced, while other genotypes were not significantly decreased at all N rates (Table 2). It showed Pioneer-11 was more affected decreasing of N fertilization rate than other genotypes. Madura local had least N content and not affected by decreasing of N rate as well as Bisma and Arjuna. The highest N uptake found in Pioneer-11 at 180 kg N/ ha. At low N, N uptake were not significantly different among genotypes tested, whereas at high N, Pioneer had higher N uptake and correlated positively in grain weight (Table 3). Gallais and Hirel (2004) reported that N uptake is less variation among genotypes tested under low N fertilization condition than under high N fertilization. At maturity, the observed low variation in whole plant N-uptake under low
Tabel 1. Grain weight, kernel number and a thousand grain weight of four maize genotypes grown under four N treatment. Genotypes Pioneer-11
N rates N/Ha)
(kg 0 60 120 180 0 60 120 180 0 60 120 180 0 60 120 180
Grain Weight (gram)
195.00 de 195.00 a 210.00 ef 342,47 cd 232.50 fg 325,11 cd 243.33 g 370,33 df Bisma 197.50 de 270,39 bcd 284.17 h 284.17 bcd 293.33 h 382,67 f 296.67 h 344,52 df Arjuna 158.33 c 238.11 a 175.83 cd 283,33 bcd 181.67 cd 272,33 bcd 185.83 de 291.67 bcd Madura 45.00 a 175.23 a 81.67 b 182.34 a 86.67 b 251.25 abc 90.83 c 240.80 ab LSD 5 % 27,03 79,79 Value followed by the same letter within each row are not significant at P ≤ 0.05 Journal of Nature Studies. 9(2)/10(1)
1000 Grain Weight (gram) 487.2 j 409.5 hij 430.3 ij 465.6 j 247.6 cde 315.6 efg 331.9 fgh 381.9 ghi 265.1 cdef 299.2 defg 319.3 efgh 382.8 ghi 126.9 a 169.0 ab 202.8 abc 231.8 abcd 79.8
Rahman and Koentjoro
N-input suggests that there was a limiting factor in nitrogen availability in the soil and in the capacity of the plant to absorb nitrogen. Unlike low N-input, at high Ninput there was a strong variation in N-uptake, with no negative correlation between yield and N-content. N uptake efficiency is ratio of N uptake/N soil and fertilizer. Among four genotypes tested showed significant interaction to N rates in N uptake efficiency. Highest N uptake efficiency was attained by Bisma, then followed by Pioneer and Arjuna, while Madura local was the least N uptake efficiency in all rates of N fertilizer. Although not significant,
low N rate tended had higher N uptake efficiency in all genotypes except the Madura local (Table 2). N utilization efficiency can be expressed as ratio harvest index/N-content of aerial parts. It is explain how agronomic efficiency of N that can be translocated into yield. There was highly significant interaction between N treatment and maize genotype. Bisma had highest N utilization efficiency at 120 Kg N/ha, while other genotypes were not significantly different in different N rates. Reduction of N rates tended to increase N utilization efficiency (Table 2).
Figure 1. Grain weight decrease due to reduction N fertilizer rates
Figure 2. Difference of grain weight between Bisma and Pioneer-11, Arjuna, Madura local
Journal of Nature Studies. 9(2)/10(1)
Genetic variation and agronomic traits associated with nitrogen use efficiency in maize
Table 2. N Uptake, N uptake efficiency, N utilization efficiency of four maize genotypes grown under four N treatment. Genotypes Pioneer-11
N rates (kg N/Ha) 0 60 120 180 0 60 120 180 0 60 120 180 0 60 120 180
N Up. Ef.
0.55 ab 0.60 ab 0.53 ab 0.68 b 0.63 ab 0.49 ab 0.60 ab 0.63 ab 0.41 ab 0.52 ab 0.65 ab 0.45 ab 0.33 a 0.42 ab 0.32 ab 0.50 ab 0.33
N Ut. Ef.
0.11 bc 0.11 bc 0.08 abc 0.09 abc 0.13 c 0.10 bc 0.07 abc 0.08 abc 0.09 abc 0.09 abc 0.10 abc 0.06 ab 0.07 ab 0.07 abc 0.05 a 0.07 ab 0.055
367.01 a 445.23 a 409.51 a 311.93 a 357.79 a 510.13 b 705.95 c 494.72 a 416.54 a 365.23 a 284.48 a 430.23 a 243.84 a 242.14 a 286.22 a 182.52 a 287.21
Value followed by the same letter within each row are not significant at P ≤ 0.05 Relationship between N Use Efficiency, root architecture and yield: Root architecture (root length, root number, root dry weight) corelated significantly to N uptake efficiency (Table 3). As morphological parameter, root architecture or root system often used to study N uptake because root is main organ of nutrient and water transportion in plant that absorb and retranslocate N associated with root architecture (Gallais, 2008). N uptake associated with root system characteristic so that genotypes selection based on root system can enhance use of N fertilizer and N soil mineralization (Feil, 1992). According to Yang and Sun (1988) root growth and root density distribution, aerobic respiration, oxidizing power, energy synthetic metabolism are the important traits responsible for higher N uptake potential. The extensive root system development is essential for N fertilizer absorption from the soil topdressed N fertilizer application.
N use efficiency had positive correlation to yield. The N uptake efficiency positively correlated with grain weight per plant based on Kendall and Spearman tests, while the N utilization efficiency positively correlated with grain weight per plant based on the Pearson test, Kendall and Spearman, it showed that NUE determines yield (Table 3). Based on N uptake efficiency, N utilization efficiency and relationship between N use efficiency and grain weight, we can be concluded that Bisma is known as the highest N use efficiency genotype among other cultivars, whereas Madura local is the least N use efficeincy so that Bisma most tolerate to low N. CONCLUSION There was genetic variation in agronomic traits and N use efficiency parameters under different N rates. Grain weight, kernel number and a thousand grain
Table 3. Relationship between root system, N uptake efficiency, N utilization and yield. Independent Variable
Root length Root number Root dry weight Total dry matter N uptake efficiency N utilization efficiency
N uptake efficiency N uptake efficiency N uptake efficiency N uptake efficiency grain weight grain weight
Sig < 0.05 significant; sig< 0.01 highly significant
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Correlation Coefficient 0.771* 0.758* 0.600* 0.465 0.454 0.815
Sig < 0.05 0. 036 0.041 0.045 0.094 0.039 0.000
Rahman and Koentjoro
weight were different in different genotypes and different N rates. Bisma was the most adaptive genotype to low-N rate and Madura local was the least. Reduction of N fertilization rate to 60 kg N/Ha stilI can be recommended cause reduced yield only less than 10%. Root architecture had positive correlation to N uptake efficiency, and NUE had positive correlation to grain weight. N uptake had less genetic variation under low N than high N. ACKNOWLEDGEMENT This study was made possible by the financial support of the Directorate General of Higher Education, Department of National Education of Indonesia through the National Strategic Grant. REFERENCES Banziger, M., Betran, F. J. & Lafitte, H. R. 1997. Efficiency of high-nitrogen selection environments for Improving maize for lownitrogen target environments. Crop Sci. 37, 1103-1109. FAO, 1995. World Agriculture: Towards 2010. an FAO study Nikos Alexandratos (ed.) Food and Agriculture Organization of the United Nations. An Wily & Sons. West Sussex. England. P 190. Feil, B.1992. Breeding Progress inSmall Grain Cereals - A Comparison of old and modern cultivars. Plant Breeding. 108: 1-11. Frink, CR, PE Waggoner, JH Ausubel. 1999. Nitrogen Fertilizer: Restropect and Prospect. Proc. Natl Acad Sci. (USA). 96: 1175-1180. Gallais, A. and Hirel, B., 2004. An Approach to the Genetics of Nitrogen Use Efficiency in Maize. Journal of Exp. Botany. 55 (396): 295-306.
Gallais, A, and Coque M. 2005. Genetic variation and selection for nitrogen use efficiency in maize: a synthesis. Maydica. 50:531-537. Gallais. 2008. Genetic variation for N remobilization and postsilking N-uptake in a set of maize recombinant inbred lines. 3. QTL detection and coincidences. Theor Appl Genet. 117:729 747. Jeuffroy M.H, Ney B., Ourry A. 2002. Integrated Physiological and Agronomic Modelling of N Capture and Use Within The Plant. Journal of Exp. Botany. 53 (370): 809-823. Lawlor D.W. 2002. Carbon and Nitrogen Assimilation in Relation to Yield. Mechanism Are The Key to Understanding Production Systems. Journal of Exp. Botany. 53 (370): 773-787. McCullough P, Girardin P, Mihajlovic M, Aguilera A, Tollenaar M. 1994. In ¯ uence of N supply on development and dry-matter accumulation of an old and a new maize hybrid. Canadian Journal of Plant Science. 74, 471 ± 477 Moll R.H. , Kamprath E.J., Jackson W.A. 1982. Analysis and Interpretation of Factors Which Contribute to Efficiency of Nitrogen Utilization. Agron. J. 74: 562-564. Raun, WR and Johnson G.V. 1999. Improving Nitrogen Use Efficiency for Cereal Production. Agron. J. 91: 357-367. Yang X, and Sun X. 1988. Physiological Characteristics of F1 Hybrid Rice N Metabolism. In Hybrid Rice. Manila (Philippines: International Rice Research Intstitute. P. 159-164.
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