Legume Research

  • Chief EditorJ. S. Sandhu

  • Print ISSN 0250-5371

  • Online ISSN 0976-0571

  • NAAS Rating 6.80

  • SJR 0.391

  • Impact Factor 0.8 (2024)

Frequency :
Monthly (January, February, March, April, May, June, July, August, September, October, November and December)
Indexing Services :
BIOSIS Preview, ISI Citation Index, Biological Abstracts, Elsevier (Scopus and Embase), AGRICOLA, Google Scholar, CrossRef, CAB Abstracting Journals, Chemical Abstracts, Indian Science Abstracts, EBSCO Indexing Services, Index Copernicus
Submit

Research Article

Legume Research, volume 43 issue 3 (june 2020) : 408-414

Grain Yield in Mungbean (Vigna radiata) is Associated with Spatial Distribution of Root Dry Weight and Volume  

Hang Zhou1, Dianfeng Zheng2,*, Naijie Feng1, Hongtao Xiang3, Yang Liu4, Xilong Liang1
1College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang-163000, China.
2College of Agriculture, Guangdong Ocean University, Zhanjiang, Guangdong-524088, China.
3Institute of Crop Cultivation and Tillage, Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang-150086, China.
4Key Laboratory of Farming System, Ministry of Agriculture, College of Agronomy and Biotechnology, China Agricultural University, Beijing-100193, China.

  • Submitted27-02-2019|

  • Accepted23-08-2019|

  • First Online 17-02-2020|

  • doi 10.18805/LR-483

Cite article:- Zhou Hang, Zheng Dianfeng, Feng Naijie, Xiang Hongtao, Liu Yang, Liang Xilong (2020). Grain Yield in Mungbean (Vigna radiata) is Associated with Spatial Distribution of Root Dry Weight and Volume . Legume Research. 43(3): 408-414. doi: 10.18805/LR-483.

ABSTRACT

Root system is an important plant organ affecting yield and the degree of influence of roots on yield in different spatial locations in the soil is different. The aim of this study was to research the spatial distribution characteristics of mung bean root and to analyze the correlation between spatial distribution of root and yield. The roots of mung bean in 0 - 5, 5 - 10, 10 - 15, 15 - 20 and 20 - 25 cm horizontal soil layers and in 0 - 20, 20 - 40, 40 - 60, 60 - 80 and 80 - 100 cm vertical soil layers were collected to analyze spatial distribution characteristics of root volume and root dry weight at full flowering stage and full pod stage. Yield and yield components were measured at maturity. Our study showed that approximately 48.4% - 65.2% of the mung bean root were in 0 - 5 cm horizontal soil layer and about 73.2% - 82.3% were in 0 - 20 cm vertical soil layer. Yield of mung bean exhibited significantly positive correlation with number of pods per plant. The root volume density of mung bean in 20 - 25 cm horizontal soil layer at full flowering stage exhibited significantly positive correlation with yield. These findings could be used to provide scientific basis for cultivating high-yield mung bean varieties with excellent root system.

INTRODUCTION

Legumes are second only to the Graminiae in their importance to humans (Graham and Vance, 2003). Grain and forage legumes account for 27% of the world’s primary crop production, with grain legumes alone contributing 33% of the dietary protein nitrogen (N) needs of humans (Vance et al., 2000). Legumes can grow in arid and N-deficient soils, acting as pioneers for soil stabilization and fertility and preventing soil erosion and desertification (Mahmoud et al., 2019). Mung bean is one of the most ancient and extensively grown legumes with the characteristics of short-term growth, strong nitrogen fixation ability and barren tolerance (Muthu et al., 2018; Patil et al., 2011). The root of mung bean is tap root system, which contain nodule having the N2-fixing bacteria Rhizobium spp. (Khan et al., 2016). It is deep rooted, much branched just like the roots of black eye (Itefa, 2016).
       
The relationship between crop yield and root has been studied extensively across different crops under different screening environments. Ehdaie et al., (2012) reported that yield of bread wheat showed positive correlation with shallow and deep root dry weight under terminal drought. The study of Kanbar et al., (2009) revealed that root dry weight had the largest effect on grain yield of rice under well-watered condition. Izumi et al., (2004) showed that root length per unit area exhibited significantly positive correlation with yield in wheat but not in soybean. Kashiwagi et al., (2006) reported that root length density at 35 days after sowing showed a significant positive correlation with yield of chickpea in field trials.
       
The distribution of root system is related to crop yield, but the key spatial location in the soil of root system affecting yield is not clear. Various workers have studied the correlation between crop root indicator and yield, but there are only few reports on the effect of mung bean root distribution on yield (Khurana and Khurana, 2014). We hypothesized that root of mung bean at different spatial locations in the soil had different effects on yield. Therefore, the objectives of this study were to estimate spatial distribution of root system of mung bean and to compute the correlation of yield with root distribution.

MATERIALS AND METHODS

Experimental site
 
The experiment was carried out at outdoor test site in National Coarse Cereals Engineering Research Center, Daqing, China on June 5, 2016.
 
Experimental devices
 
There were two kinds of devices: horizontal device and vertical device (Fig 1). The horizontal device was a cylindrical metal barrel with a diameter of 50 cm and a height of 50 cm, which was fixed with a cross steel frame with a length of 54 cm on both sides of the metal barrel. The inside of the metal barrel was equipped with a diameter of 10 cm, 20 cm, 30 cm and 40 cm of metal net. The distance between the metal net was 5 cm and the metal net was fixed on the cross steel frame by nylon straps (Fig 2). The vertical device was a cylindrical plastic barrel with a diameter of 30 cm and a height of 150 cm (Fig 3). In order to facilitate sampling, inside the vertical device was a plastic water belt of 30 cm in diameter and the soil was filled in the plastic water belt (Fig 4). The lower end of the plastic water belt was sealed and four round holes were cut using scissors.
 

Fig 1: A: Vertical device, which was a cylindrical plastic barrel with a diameter of 30 cm and a height of 150 cm; B: Horizontal device, which was a cylindrical metal barrel with a diameter of 50 cm and a height of 50 cm.


 

Fig 2: Horizontal device entity.


 

Fig 3: Vertical device entity.


 

Fig 4: The plastic water belt of 30 cm in diameter inside the vertical device and the soil was filled in the plastic water belt.


 
Soil characteristics
 
The soil obtained from fall of the previous year (2015) was used in the experiment. The soil was screened before pouring into the devices to remove grass root, tree root and large granular clods and stones and the filtered soil was mixed with sand in a 3:1 ratio. Repeated infusion of soil and water was undertaken, so that the soil became tight until soil was not sinking when water was refilled. This water and soil blend was maintained in the field environment during the winter and spring.
 
Experiment design, species and seeding
 
Mung bean cultivar Jilv7 and Gonglv2 were planted at five seeds per barrel separately in 48 barrels which included 24 horizontal devices and 24 vertical devices. Two seedlings were retained and grown with four replications per growth stage and type of device.
 
Root sample collection
 
Soil samples for root measurements were taken from the devices at full flowering stage and full pod stage. The number of pods per plant, number of seeds per pod and yield were measured at maturity. In horizontal devices, the center of the cross section of the column was taken as the starting point to obtain the mung bean root samples in the horizontal direction i.e. 0-5 cm, 5-10 cm, 10-15 cm, 15-20 cm and 20-25 cm layers. In vertical devices, the upper soil surface was taken as the starting point to obtain soil samples with root in 0-20 cm, 20-40 cm, 40-60 cm, 60-80 cm and 80-100 cm soil layers in vertical direction. The plants were clipped at cotyledons by scissors before sampling. Soil samples containing root were soaked in a plastic bucket filled with water until the soil became soft and then filtered. The obtained root samples were washed with clean tap water and then placed in a plastic, sealable bag and the bag was placed in a refrigerator for further use.
 
Data collection
 
The harvested root samples were placed in a clear glass tray filled with water. The roots were washed to remove soil particles and other dirt that could hamper efficient scanning of root samples. The glass tray was placed on a scanner (Epson V700) and digital images were generated at 400 dpi. Digital image analysis of mung bean root samples was conducted using WinRHIZO (version 2014a, Reagent Instruments Inc., Quebec, Canada) and the data included root volume, from which root volume density (RVD) was estimated as follows:

                  
Where,
V is the root volume, V0 is the soil volume, r is the radius and h is the height.
       
After scanning, the roots were removed from glass tray and subsequently were placed in an oven at 105°C for 2 hours, then drying to constant weight in 75°C oven. The dry weight of roots was obtained by analytical balance and the root dry weight density (RDWD) was estimated as:
 
                          
Where,
M is the root dry weight.
 
Statistical analysis
 
Pearson Correlation Analysis was used to evaluate the relationships between different traits by SPSS 22. Figure preparation was carried out by MicroCal Origin software 2017 (OriginLab).

RESULTS AND DISCUSSION

The spatial distribution of root volume density
 
Root volume is an important factor in drawing up moisture and nutrients from the soil for the plants, reflecting the size of rooting systems (Fageria, 2005). In horizontal devices, mung bean had the largest root volume density in 0-5 cm horizontal soil layer. With the increase of distance from the main root, the root volume density decreased gradually. The root volume of Jilv7 in 0-5 cm horizontal soil layer were 18.4% and 21.0% of the total root volume at full flowering stage and full pod stage, respectively. And Gonglv2 had 18.1% and 29.1% of the total root volume in 0-5 cm horizontal soil layer at full flowering stage and full pod stage, respectively. Compared with full flowering stage, the ratio of root volume in 0 - 5 cm horizontal soil layer to total root volume of both two mung beans increased at full pod stage (Fig 5).
 

Fig 5: Changes in different horizontal soil layers of root volume density of two mung bean cultivars Jilv7 and Gonglv2 at full flowering stage and full pod stage. Bars represent standard error.


       
In vertical devices, the maximum root volume density of mung beans was found in 0-20 cm vertical soil layer. 20-40 cm and 40-60 cm vertical soil layers also had a large proportion of root volume. The root volume of Jilv7 in 0-20 cm vertical soil layer were 67.5% and 60.5% of the total root volume at full flowering stage and full pod stage, respectively. For Gonglv2, 71.0% and 62.1% of total root volume were found in 0-20 cm vertical soil layer at full flowering stage and full pod stage, respectively. This agrees with Gan et al., (2011) who found that 59% of the total root volume of pulses were in 0-20 cm soil layer. From full flowering stage to full pod stage, the proportion of root volume in deep soil layer increased (Fig 6).
 

Fig 6: Changes in different vertical soil layers of root volume density of two mung bean cultivars Jilv7 and Gonglv2 at full flowering stage and full pod stage. Bars represent standard error.


 
The spatial distribution of root dry weight density
 
Root dry weight density can be used as an indicator to express root extension and distribution (Adiku et al., 2001). In horizontal devices, the maximum root dry weight density of mung beans were found in 0-5 cm horizontal soil layer. 48.4% and 56.8% of total root dry weight of Jilv7 were found in 0-5 cm horizontal soil layer at full flowering stage and full pod stage, respectively. Gonglv2 had 53.7% and 65.2% of total root dry weight in 0-5 cm horizontal soil layer at full flowering stage and full pod stage, respectively. This agreed with the study of Gao et al., (2010) in soybean and maize. Compared to other soil layers, the root dry weight density in 20-25 cm horizontal soil layer were the minimum (Fig 7).
 

Fig 7: Changes in different horizontal soil layers of root dry weight density of two mung bean cultivars Jilv7 and Gonglv2 at full flowering stage and full pod stage. Bars represent standard error.


       
In vertical devices, the maximum dry weight density of mung beans were found in 0-20 cm vertical soil layer. With the increase of soil layer depth, the root dry weight density decreased gradually. In 0-20 cm vertical soil layer, 82.3% and 75.5% of total dry weight of Jilv7, 74.0% and 73.2% of total dry weight of Gonglv2 were found at full flowering stage and full pod stage, respectively. Similar results were reported by Benjamin and Nielsen (2006) in soybean. The proportion of root dry weight of two mung beans in deep soil layers at full pod stage decreased compared to full flowering stage (Fig 8).
 

Fig 8: Changes in different vertical soil layers of root dry weight density of two mung bean cultivars Jilv7 and Gonglv2 at full flowering stage and full pod stage. Bars represent standard error.


 
The spatial distribution of mung beans’ root dry weight density showed that the root dry weight density tended to decrease gradually with the deepening of the soil layer and the increasing of the distance from the taproot.
 
Correlations
 
The yield traits such as number of pods per plant, number of seeds per pod and seed yield were measured at maturity (Table 4). Yield of Jilv7 showed significantly positive correlation with the number of pods per plant (r = 0.964**) and yield of Gonglv2 also had significantly positive correlation with the number of pods per plant (r = 0.871**) (Table 1). This was same as the results of Makeen et al., (2007) and Tabasum et al., (2010). The increase in the number of pods per plant may increase the yield of mung bean.
 

Table 1: Correlation coefficients between yield and yield components of mung bean cultivars Jilv7 and Gonglv2.


 

Table 4: Yield and yield components of mung bean cultivars Jilv7 and Gonglv2 in vertical devices and horizontal devices.


       
In horizontal direction, the root volume density of Jilv7 in 20-25 cm horizontal soil layer showed significantly positive correlation (r = 0.960*) with yield at full flowering stage. The root volume density of Gonglv2 in 10-15 cm (r = 0.976*) and 20 - 25 cm (0.982*) horizontal soil layers at full flowering stage showed significantly positive correlation with yield, respectively. The root dry weight density of Gonglv2 in 20-25 cm horizontal soil layer had significantly positive correlation (r = 0.954*) with yield at full pod stage (Table 2). In vertical direction, the yield of Jilv7 showed significantly positive correlation (r = 0.988*) with root volume density in 40-60 cm soil layer at full pod stage (Table 3). These traits were the most important yield contributing traits of mung beans for increasing yield.
 

Table 2: Correlation coefficients between yield and root volume density (m3 m-3) and root dry weight density (kg· m-3) of mung bean cultivars Jilv7 and Gonglv2 in different horizontal soil layers at full flowering stage and full pod stage.


 

Table 3: Correlation coefficients between yield and root volume density (m3 m-3) and root dry weight density (kg· m-3) of mung bean cultivars Jilv7 and Gonglv2 in different vertical soil layers at full flowering stage and full pod stage.

CONCLUSION

The highest density of mung bean root was in 0-5 cm horizontal soil layer and in 0-20 cm vertical soil layer. Approximately 48.4%-65.2% of the mung bean root were in 0-5 cm horizontal soil layer and 73.2% - 82.3% were in 0-20 cm vertical soil layer.
       
The number of pods per plant was the most important yield components of mung bean. The root volume density in 20-25 cm horizontal soil layer at full flowering stage was the most inportant roots morphology indicator of mung bean to increase yield. These traits can be used in high yield breeding of mung bean.

ACKNOWLEDGEMENT

The authors gratefully acknowledge the technical support of Prof. Dianfeng Zheng and Prof. Naijie Feng, language modification of Seth Kutikoff from Kansas State University and financial support provided by the project of Key Technology Research and Demonstration on High-efficiency Production of Coarse Beans (2014BAD07B05).

REFERENCES


  1. Adiku, S.G., Ozier-Lafontaine, H. and Bajazet, T. (2001). Patterns of root growth and water uptake of a maize-cowpea mixture grown under greenhouse conditions. Plant and Soil. 235: 85-94. 

  2. Benjamin, J.G. and Nielsen, D.C. (2006). Water deficit effects on root distribution of soybean, field pea and chickpea. Field Crops Research. 97: 248-253. 

  3. Ehdaie, B., Layne, A.P. and Waines, J.G. (2012). Root system plasticity to drought influences grain yield in bread wheat. Euphytica. 186: 219-232. 

  4. Fageria, N.K. (2005). Influence of dry matter and length of roots on growth of five field crops at varying soil zinc and copper levels. Journal of Plant Nutrition. 27: 1517-1523.

  5. Graham, P.H. and Vance, C.P. (2003). Legumes: importance and constraints to greater use. Plant Physiology. 131: 872-877.

  6. Gan, Y., Liu, L., Cutforth, H., Wang, X. and Ford, G. (2011). Vertical distribution profiles and temporal growth patterns of roots in selected oilseeds, pulses and spring wheat. Crop and Pasture Science. 62: 457-466. 

  7. Gao, Y., Duan, A., Qiu, X., Liu, Z., Sun, J., Zhang, J. and Wang, H. (2010). Distribution of roots and root length density in a maize/    soybean strip intercropping system. Agricultural Water Management. 98: 199-212.

  8. Izumi, Y., Uchida, K. and Iijima, M. (2004). Crop production in successive wheat-soybean rotation with no-tillage practice in relation to the root system development. Plant Production Science. 7: 329-336. 

  9. Itefa, D. (2016). General characteristics and genetic improvement status of mungbean (Vigna radiata L.) in Ethiopia: Review article. International Journal of Agriculture Innovations and Research. 5: 2319-1473.

  10. Kashiwagi, J., Krishnamurthy, L., Crouch, J.H. and Serraj, R. (2006). Variability of root length density and its contributions to seed yield in chickpea (Cicer arietinum L.) under terminal drought stress. Field Crops Research. 95: 171-181. 

  11. Kanbar, A., Toorchi, M. and Shashidhar, H. (2009). Relationship between root and yield morphological characters in rainfed low land rice (Oryza sativa L.). Cereal Research Communications. 37: 261-268. 

  12. Khurana, M.P.S. and Jhanji, S. (2014). Influence of cadmium on dry matter yield, micronutrient content and its uptake in some crops. Journal of Environmental Biology. 35: 865-870.

  13. Khan, M.R., Mohidin, F. A., Khan, U. and Ahamad, F. (2016). Native Pseudomonas spp. suppressed the root-knot nematode in in vitro and in vivo and promoted the nodulation and grain yield in the field grown mungbean. Biological Control. 101: 159-168.

  14. Makeen, K., Abrahim, G., Jan, A. and Singh, A.K. (2007). Genetic variability and correlations studies on yield and its components in mungbean [Vigna radiata (L.) wilezek]. Journal of Agronomy. 6: 216-218. 

  15. Muthu, M.C., Sushree, A. and Srivastava, R. (2018). Influence of production factors on seed quality parameters of green gram (Vignaradiata) CV. KKM-3. Legume Research. 41: 891-894.

  16. Mahmoud, M.A., Mart, D. and Can, C. (2019). Phenotypic characterization of indigenous rhizobia nodulating chickpea in Turkey reveals high diversity. Legume Research. 42: 379-384.

  17. Patil, A.B., Desai, N.C., Mule, P.N. and Khandelwal, V. (2011). Combining ability for yield and component characters in mungbean [Vigna radiata (L.) Wilczek.]. Legume Research. 34: 190-195.

  18. Tabasum, A., Saleem, M. and Aziz, I. (2010). Genetic variability, trait association and path analysis of yield and yield components in mungbean [Vigna radiata (L.) Wilczek]. Pakistan Journal of Botany. 42: 3915-3924. 

  19. Vance, C.P., Graham, P.H. and Allan, D.L. (2000). Biological nitrogen fixation. Phosphorus: a critical future need. In: Nitrogen Fixation: From Molecules to Crop Productivity. (Pedrosa FO, Hungria M, Yates MG, Newton WE (eds). Kluwer Academic Publishers, Netherlands. pp. 506-514.
Reviewed By

Download Article
In this Article
    Contact us
    Follow us

    Editorial Board

    View all (0)