Hybrid variation for root system efficiency in maize: potential links to drought adaptation

2016 ◽  
Vol 43 (6) ◽  
pp. 502 ◽  
Author(s):  
Erik J. van Oosterom ◽  
Zongjian Yang ◽  
Fenglu Zhang ◽  
Kurt S. Deifel ◽  
Mark Cooper ◽  
...  

Water availability can limit maize (Zea mays L.) yields, and root traits may enhance drought adaptation if they can moderate temporal patterns of soil water extraction to favour grain filling. Root system efficiency (RSE), defined as transpiration per unit leaf area per unit of root mass, represents the functional mass allocation to roots to support water capture relative to the allocation to aerial mass that determines water demand. The aims of this study were to identify the presence of hybrid variation for RSE in maize, determine plant attributes that drive these differences and illustrate possible links of RSE to drought adaptation via associations with water extraction patterns. Individual plants for a range of maize hybrids were grown in large containers in shadehouses in Queensland, Australia. Leaf area, shoot and root mass, transpiration, root distribution and soil water were measured in all or selected experiments. Significant hybrid differences in RSE existed. High RSE was associated with reduced dry mass allocation to roots and more efficient water capture per unit of root mass. It was also weakly negatively associated with total plant dry mass, reducing preanthesis water use. This could increase grain yield under drought. RSE provides a conceptual physiological framework to identify traits for high-throughput phenotyping in breeding programs.

2009 ◽  
Vol 13 (3) ◽  
pp. 257-261 ◽  
Author(s):  
Adriana L. da Silva ◽  
Isabeli P. Bruno ◽  
Klaus Reichardt ◽  
Osny O. S. Bacchi ◽  
Durval Dourado-Neto ◽  
...  

Basic information for a rational soil-water management of the coffee crop is still insufficient, particularly under irrigated conditions. Of great importance for the estimation of water requirements of coffee crops are their root distribuition and evapotranspiration crop coefficients. This study compares soil water extraction by roots of coffee plants of the variety "Catuaí Vermelho" (IAC-44), grown in Piracicaba, SP, Brazil, 3 to 5 years old, with direct measurements of root dry matter, showing a good agreement between both approaches, and confirming that most of the root system is distributed in the top soil layer (0-0.3 m) and that less than 10% of the root system reaches depths greater than 1.0 m. Calculated evapotranspiration crop coefficients are in agreement with those found in the literature, with an average of 1.1, independent of shoot dry matter, plant height and leaf area index.


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 428D-428
Author(s):  
Thomas E. Marler ◽  
Haluk M. Discekici

`Known You 1' papaya seedlings were grown in split-root containers and fertilizer was applied to one (1/2) or two (2/2) halves of the root system to determine the influence on transport of assimilates from canopy to roots and transport of nitrogen from fertilized roots to non-fertilized roots and canopy. Following 6 weeks of growth, the plants were bare-rooted and the root system halves and canopy were dried to constant mass at 70°C. Tissue was then analyzed for total nitrogen content. Fertilization increased root mass more than 250% and total plant mass 300% compared with control plants, which received no fertilization during the 6 weeks. Total root or plant mass did not differ between the 1/2 and 2/2 plants. Roots were evenly distributed between the two halves for 2/2 plants, but the fertilized half in the 1/2 plants accounted for 60% of the total root mass. Nitrogen content of roots and canopy were increased by fertilization. Nitrogen content of the non-fertilized roots of 1/2 plants was not different from that of the fertilized roots. These results indicate that fertilizing a portion of the papaya root system increased the sink activity of that portion and that the absorbed nitrogen from that portion is efficiently transported throughout the plant.


2011 ◽  
Vol 38 (5) ◽  
pp. 347 ◽  
Author(s):  
Jairo A. Palta ◽  
Xing Chen ◽  
Stephen P. Milroy ◽  
Greg J. Rebetzke ◽  
M. Fernanda Dreccer ◽  
...  

There is little consensus on whether having a large root system is the best strategy in adapting wheat (Triticum aestivum L.) to water-limited environments. We explore the reasons for the lack of consensus and aim to answer the question of whether a large root system is useful in adapting wheat to dry environments. We used unpublished data from glasshouse and field experiments examining the relationship between root system size and their functional implication for water capture. Individual root traits for water uptake do not describe a root system as being large or small. However, the recent invigoration of the root system in wheat by indirect selection for increased leaf vigour has enlarged the root system through increases in root biomass and length and root length density. This large root system contributes to increasing the capture of water and nitrogen early in the season, and facilitates the capture of additional water for grain filling. The usefulness of a vigorous root system in increasing wheat yields under water-limited conditions maybe greater in environments where crops rely largely on seasonal rainfall, such as the Mediterranean-type environments. In environments where crops are reliant on stored soil water, a vigorous root system increases the risk of depleting soil water before completion of grain filling.


2016 ◽  
Vol 43 (2) ◽  
pp. 173 ◽  
Author(s):  
Sarah M. Rich ◽  
Anton P. Wasson ◽  
Richard A. Richards ◽  
Trushna Katore ◽  
Renu Prashar ◽  
...  

Many rainfed wheat production systems are reliant on stored soil water for some or all of their water inputs. Selection and breeding for root traits could result in a yield benefit; however, breeding for root traits has traditionally been avoided due to the difficulty of phenotyping mature root systems, limited understanding of root system development and function, and the strong influence of environmental conditions on the phenotype of the mature root system. This paper outlines an international field selection program for beneficial root traits at maturity using soil coring in India and Australia. In the rainfed areas of India, wheat is sown at the end of the monsoon into hot soils with a quickly receding soil water profile; in season water inputs are minimal. We hypothesised that wheat selected and bred for high yield under these conditions would have deep, vigorous root systems, allowing them to access and utilise the stored soil water at depth around anthesis and grain-filling when surface layers were dry. The Indian trials resulted in 49 lines being sent to Australia for phenotyping. These lines were ranked against 41 high yielding Australian lines. Variation was observed for deep root traits e.g. in eastern Australia in 2012, maximum depth ranged from 118.8 to 146.3 cm. There was significant variation for root traits between sites and years, however, several Indian genotypes were identified that consistently ranked highly across sites and years for deep rooting traits.


2013 ◽  
Vol 404 ◽  
pp. 415-419
Author(s):  
Heng Jia Zhang ◽  
Jun Hui Li

The soil water contents in spring maize field were monitored continuously using soil neutron probe combined with drying-weighing method. Meanwhile, the effect of limited irrigation on crop periodic water consumption and its percentage in total water use, leaf area index, and grain yield of spring maize were explored. The results indicated that both the periodic water consumption and its percentage in total water use varied from low to high then to low within maize growing season, with the maximum valued both at silking to middle grain filling. In addition, leaf area indexes were greatly improved by full irrigation before maize filling, and grain yield was not reduced by efficient limited irrigation management, contrarily, yield increase and 31.1% of significant irrigation water saving were achieved, which was beneficial to the optimization of soil water ecological processing and limited irrigation management.


Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1048
Author(s):  
Paul L. A. Melo ◽  
Maurício R. Cherubin ◽  
Tamara C. A. Gomes ◽  
Izaias P. Lisboa ◽  
Lucas S. Satiro ◽  
...  

The sugarcane (Saccharum spp. L.) mechanical harvesting system leaves a large amount of straw mulch on the soil surface. The straw mulch may affect soil conditions, root regrowth, and sugarcane yield. Thus, this study assessed the response of sugarcane root system growth and stalk yield to different rates of straw removal. An experiment was conducted in a Rhodic Kandiudox with sand clay loam texture to test the impact of four rates of straw removal: no removal (18.9 Mg ha−1 of dry mass); moderate removal (8.7 Mg ha−1); high removal (4.2 Mg ha−1) and total removal on sugarcane root system and stalk yield. Higher concentrations of roots (60%) were found in the first 40 cm of soil. Moderate straw removal resulted in higher root mass (3.6 Mg ha−1) and stalk production (23 Mg ha−1 of dry mass). However, no straw removal reduced root mass by <40% (2099 kg ha−1) and reduced stalk yield by >20% (105 Mg ha−1). Through regression analysis, it was estimated that retaining between 8.5 and 13 Mg ha−1 of straw resulted in the highest root mass and stalk yield. Managing straw removal to retain a moderate amount enables producers to sustain suitable soil conditions for sugarcane root growth and stalk production while providing straw for industrial use.


2019 ◽  
Vol 11 (4) ◽  
pp. 493
Author(s):  
Franciely Magalhães Barroso ◽  
Paulo Henrique Pereira Costa Muniz ◽  
Mariany Dalila Milan ◽  
Wanderson Silva dos Santos ◽  
Natália Cássia de Faria Ferreira ◽  
...  

The growth of plants by the use of Trichoderma occurs through distinct mechanisms, among which it can highlight the synthesis of phytohormones and auxins analogues. The objective of this work was to evaluate Trichoderma spp. commercial strains in the promoting seedlings growth and in the productivity of parsley plants. In laboratory assay, seeds of parsley cv. &lsquo;Gra&uacute;da Portuguesa&rsquo; were treated with 2 mL of Trichoderma suspension (2.5 &times; 108 ml-1 conidia per 100 g of seeds) submitted to growth test until 28 days after sowing (DAS). For the greenhouse experiment, parsley seedlings were transplanted into 3.0 L pots containing soil, which was previously treated with 5 mL Trichoderma suspension, totaling 1.5 &times; 108 conidia per pot. In both, a control without Trichoderma application was included, being arranged in a completely randomized design (CRD). The evaluations were: percentage of germination (PG), root length (RL), shoot length (SL), total length (TL = RL + SL), fresh root mass (FRM), fresh shoot mass (FSM), total fresh mass (TFM = FRM + FSM), root dry mass (RDM), shoot dry mass (SDM), total dry mass (BIO = RDM + SDM), root mass ratio (RMR = RDM/BIO), shoot mass ratio (SMR = SDM/BIO), aerial part/root system retio (AP/RS = SDM/RDM) and productivity at 110 DAS. Althougth no diferences was observed among the Trichoderma treatments and the control about yield, Trichoderma spp. strains provided better TFM (18.98 to 22.92 mg), BIO (3.37 to 4.31 mg) and root system superior to the control (14.20 and 2.44 mg, respectively) under greenhouse conditions. T. harzianum ESALQ1306 was the better strain in laboratory assyas, suggsting this isolate for applied in the seeds when it aims the promotion of initial growth.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 685b-685
Author(s):  
Thomas E. Marler ◽  
Haluk M. Discekici

`Red Lady' papaya transplants were planted on a slope with a 30% to 35% grade and grown for 5 months. Excavation was used to determine root distribution on the uphill and downhill sides of the plants. Roots were separated into the taproot system and lateral roots on the uphill and downhill sides. The line intersect method was used to determine length of the lateral roots, and length of the taproot system was measured directly. All roots were dried at 70°C. The taproot system accounted for 2% of the total root length and 66% of the total root mass. Of the 130-m of lateral roots, 71% were located on the downhill side. Similarly, 69% of the dry mass of the lateral root system was located on the downhill side. Primary lateral roots on the uphill side of each plant developed horizontally, but some secondary lateral roots developed against gravity to maintain a portion of the root system close to the surface of the slope. Some of these lateral roots developed at angles of 55° to 60° above the horizontal.


Efficiency of combination of soil herbicide Command (CE 0.02 ml/m2) and growth stimulators Melafen and Emistim S for tobacco seedling growing in sheltered ground has been studied. Before studies inhibition properties of herbicide on first stage of tobacco growing were found. For decreasing effect of herbicide ’s depression and increasing growing processes researches during greenhouse and field stages have been carried. It has been found that soaking seeds in solution of growth stimulator Melafen (concentration 0.05 %) and Emistim S (concentration 0.00001 %) during 3 hours in combination with further treatments on basic stages of seedling development (cotyledon and ready for transplanting before pulling out) led not only to decreasing toxic effect of herbicide but also increasing qualitative properties of tobacco plants. Growth stimulators led to increasing length of plants from collar to growing point by 46-62 %, to end of tips - by 20-35 %, above ground plant mass - by 42 - 86 %, root mass - by 32 %. It was also noticed 28 - 36 % increasing outcome of standard seedlings from m2 in time of transplanting. Due to prolonged effect of Melafen and Emistim S seedlings transplanted into field were with increased surviving properties. Later, due to increased growing rate it was noticed increasing leaf area by 9-18 % and productivity - by 16-24 %. Economic effect due to utilizing growth stimulators Melafen and Emistim S during seedling stage reaches 360 and 470 rubles/m2 and during field stage - 66 and 98 th.rubles/ha respectively. Offered elaboration can be utilized for protecting systems of different agricultural plants where utilizing soil herbicides is recommended. Also quality of cured tobacco grown with stimulators had been improved.


Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 174
Author(s):  
Hui Liu ◽  
Fabio Fiorani ◽  
Ortrud Jäck ◽  
Tino Colombi ◽  
Kerstin A. Nagel ◽  
...  

Plants with improved nutrient use efficiency are needed to maintain and enhance future crop plant production. The aim of this study was to explore candidate traits for pre-breeding to improve nutrient accumulation and early vigor of spring wheat grown at high latitudes. We quantified shoot and root traits together with nutrient accumulation in nine contrasting spring wheat genotypes grown in rhizoboxes for 20 days in a greenhouse. Whole-plant relative growth rate was here correlated with leaf area productivity and plant nitrogen productivity, but not leaf area ratio. Furthermore, the total leaf area was correlated with the accumulation of six macronutrients, and could be suggested as a candidate trait for the pre-breeding towards improved nutrient accumulation and early vigor in wheat to be grown in high-latitude environments. Depending on the nutrient of interest, different root system traits were identified as relevant for their accumulation. Accumulation of nitrogen, potassium, sulfur and calcium was correlated with lateral root length, whilst accumulation of phosphorus and magnesium was correlated with main root length. Therefore, special attention needs to be paid to specific root system traits in the breeding of wheat towards improved nutrient accumulation to counteract the suboptimal uptake of some nutrient elements.


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