Tolerance of wheat cultivars to root‐lesion nematode ( Pratylenchus thornei ) assessed by normalised difference vegetation index is predictive of grain yield

2019 ◽  
Vol 174 (3) ◽  
pp. 388-401 ◽  
Author(s):  
Neil A. Robinson ◽  
Jason G. Sheedy ◽  
Bethany J. MacDonald ◽  
Kirsty J. Owen ◽  
John P. Thompson
Keyword(s):  
Grain Yield ◽  
Vegetation Index ◽  
Wheat Cultivars ◽  
Root Lesion Nematode ◽  
Pratylenchus Thornei ◽  
Normalised Difference Vegetation Index ◽  
Lesion Nematode

scholarly journals Impacts of Root-Lesion Nematode (Pratylenchus thornei) on Plant Nutrition, Biomass, Grain Yield and Yield Components of Susceptible/Intolerant Wheat Cultivars Determined by Nematicide Applications

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 296
Author(s):  
John P. Thompson ◽  
Timothy G. Clewett
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Root Zone ◽  
Wheat Cultivars ◽  
Root Lesion Nematode ◽  
Population Densities ◽  
Poor Growth ◽  
Pratylenchus Thornei ◽  
Lesion Nematode ◽  
The Impact

Field experiments testing rates of various nematicides, with and without NPZn fertiliser, were analysed to investigate how root-lesion nematode (Pratylenchus thornei) affects growth and yield components of susceptible/intolerant wheat cultivars in a subtropical environment. Plant response to nematode attack was assessed by regression and principal components analyses of various plant parameters at different crop development stages, in relation to different nematode population densities in the roots and root-zone soil. Reduction in P. thornei population densities by nematicides resulted in increased numbers of tillers, plant biomass, N and P concentrations and uptakes, numbers of spikes and kernels, and grain yield. Grain yield was strongly correlated with number of kernels, biomass and number of spikes, and negatively correlated with number of P. thornei in the root-zone soil at stem elongation. This study showed that P. thornei damage to roots decreased wheat yield through limiting N and P concentrations and uptakes in plant tops causing poor growth that commenced early and continued through the life of the crop. Genetic, environmental and management factors that reduce population densities of P. thornei, and decrease the impact of the nematodes starting in early crop growth, will greatly increase spike and kernel numbers and grain yield.

Wheat biomass and yield increased when populations of the root-lesion nematode (Pratylenchus thornei) were reduced through sequential rotation of partially resistant winter and summer crops

2014 ◽  
Vol 65 (3) ◽  
pp. 227 ◽  
Author(s):  
K. J. Owen ◽  
T. G. Clewett ◽  
K. L. Bell ◽  
J. P. Thompson
Keyword(s):  
Grain Yield ◽  
Crop Rotation ◽  
Yield Loss ◽  
Soil Depth ◽  
Wheat Yield ◽  
Broad Host Range ◽  
Root Lesion Nematode ◽  
Pratylenchus Thornei ◽  
Host Status ◽  
Lesion Nematode

The root-lesion nematode, Pratylenchus thornei, can reduce wheat yields by >50%. Although this nematode has a broad host range, crop rotation can be an effective tool for its management if the host status of crops and cultivars is known. The summer crops grown in the northern grain region of Australia are poorly characterised for their resistance to P. thornei and their role in crop sequencing to improve wheat yields. In a 4-year field experiment, we prepared plots with high or low populations of P. thornei by growing susceptible wheat or partially resistant canaryseed (Phalaris canariensis); after an 11-month, weed-free fallow, several cultivars of eight summer crops were grown. Following another 15-month, weed-free fallow, P. thornei-intolerant wheat cv. Strzelecki was grown. Populations of P. thornei were determined to 150 cm soil depth throughout the experiment. When two partially resistant crops were grown in succession, e.g. canaryseed followed by panicum (Setaria italica), P. thornei populations were <739/kg soil and subsequent wheat yields were 3245 kg/ha. In contrast, after two susceptible crops, e.g. wheat followed by soybean, P. thornei populations were 10 850/kg soil and subsequent wheat yields were just 1383 kg/ha. Regression analysis showed a linear, negative response of wheat biomass and grain yield with increasing P. thornei populations and a predicted loss of 77% for biomass and 62% for grain yield. The best predictor of wheat yield loss was P. thornei populations at 0–90 cm soil depth. Crop rotation can be used to reduce P. thornei populations and increase wheat yield, with greatest gains being made following two partially resistant crops grown sequentially.

scholarly journals Resistance of Wheat Genotypes to Root-Lesion Nematode (Pratylenchus thornei) Can be Used to Predict Final Nematode Population Densities, Crop Greenness, and Grain Yield in the Field

2020 ◽  
Vol 110 (2) ◽  
pp. 505-516 ◽  
Author(s):  
J. P. Thompson ◽  
J. G. Sheedy ◽  
N. A. Robinson
Keyword(s):  
Grain Yield ◽  
Nematode Population ◽  
Root Lesion Nematode ◽  
Population Densities ◽  
Wheat Genotypes ◽  
Final Population ◽  
Pratylenchus Thornei ◽  
Principal Axes ◽  
Australian Wheat ◽  
Lesion Nematode

The root-lesion nematode Pratylenchus thornei is a major pathogen of wheat (Triticum aestivum) in many regions globally. Resistance of wheat genotypes to P. thornei can be determined from final nematode population densities in glasshouse experiments but combining results across multiple experiments presents challenges. Here, we use a factor analytic method for multiexperiment analysis of final population densities of P. thornei for 1,096 unique wheat genotypes in 22 glasshouse experiments. The resistance to P. thornei of the genotypes was effectively represented by a two-factor model with rotation of the axes to a principal components solution. Principal axes 1 and 2 (PA1 and PA2) accounted for 79 and 11% of the genetic variance, respectively, over all experiments. Final population densities of P. thornei as empirical best linear unbiased predictors (PA[1+2]-eBLUPs) from the combined glasshouse experiments were highly predictive (P < 0.001) of final nematode population densities in the soil profile, crop canopy greenness (normalized difference vegetation index), and grain yield of wheat genotypes in P. thornei-infested fields in the Australian subtropical grain region. Nine categories of resistance ratings for wheat genotypes from resistant to very susceptible were based on subdivision of the range of PA(1+2)-eBLUPs for use in growers’ sowing guides. Nine genotypes were nominated as references for future resistance experiments. Most (62%) Australian wheat genotypes were in the most susceptible three categories (susceptible, susceptible to very susceptible, and very susceptible). However, resistant germplasm characterized in this study could be used in plant breeding to considerably improve the overall resistance of Australian wheat crops.

Metabolomic profiling of wheat genotypes resistant and susceptible to root-lesion nematode Pratylenchus thornei

2021 ◽  
Author(s):  
Md Motiur Rahaman ◽  
Rebecca S. Zwart ◽  
Thusitha W. T. Rupasinghe ◽  
Helen L. Hayden ◽  
John P. Thompson
Keyword(s):  
Root Lesion Nematode ◽  
Wheat Genotypes ◽  
Metabolomic Profiling ◽  
Pratylenchus Thornei ◽  
Lesion Nematode

Fine mapping of root lesion nematode (Pratylenchus thornei) resistance loci on chromosomes 6D and 2B of wheat

2019 ◽  
Vol 133 (2) ◽  
pp. 635-652 ◽  
Author(s):  
Muhammad Shefatur Rahman ◽  
Katherine J. Linsell ◽  
Julian D. Taylor ◽  
Matthew J. Hayden ◽  
Nicholas C. Collins ◽  
...  
Keyword(s):  
Fine Mapping ◽  
Root Lesion Nematode ◽  
Pratylenchus Thornei ◽  
Lesion Nematode

Use of normalised difference vegetation index, nitrogen concentration, and total nitrogen content of whole maize plant and plant fractions to estimate yield and nutritive value of hybrid forage maize

2011 ◽  
Vol 62 (5) ◽  
pp. 374 ◽  
Author(s):  
M. R. Islam ◽  
S. C. (Yani) Garcia ◽  
D. Henry
Keyword(s):  
Grain Yield ◽  
Multiple Regression ◽  
Vegetation Index ◽  
Nutritive Value ◽  
Biomass Yield ◽  
Maize Plant ◽  
Forage Maize ◽  
Leaf Stage ◽  
Whole Plant ◽  
Normalised Difference Vegetation Index

This study was conducted to investigate the potentials of normalised difference vegetation index (NDVI), nitrogen (N) concentration (%), and N content (g/plant) of whole maize plant to estimate yield and nutritive value of hybrid forage maize. Hybrid forage maize was grown with two rates of pre-sowing fertiliser N (0, 135 kg/ha) and three rates of post-sowing fertiliser N (0, 79, 158 kg N/ha) applied at the six-leaf stage. Data on the NDVI and N (% and g/plant) of maize were collected at 2-, 3-, 6-, 8-, 12-, 16-, 18-leaf stages and at harvest. Metabolisable energy (ME) content of the whole maize plant at harvest was estimated from in vitro digestibility. Simple, polynomial, and multiple regression analyses were conducted and only the best-fit models were selected. The 8-leaf stage was found to be the most effective stage for use of the NDVI in predicting biomass yield (R2 = 0.81), grain yield (R2 = 0.72), and N (%) (R2 = 0.92) of forage maize. Nitrogen (%) at the 8-leaf stage was also best related to biomass yield (R2 = 0.88). Multiple regressions at the 3-leaf stage increased the coefficient of determination for both biomass yield and grain yield (R2 = 0.77) over the relationships obtained from N (%) of the whole plant at 2- or 3-leaf stage. The NDVI and N (%) of the whole plant at 8-leaf stage were the best predictors of yield, but failed to predict ME content of the hybrid forage maize. Multiple regression models at the 3-leaf stage were almost as effective as the NDVI and N (%) of whole maize plant at the 8-leaf stage in predicting biomass and grain yield of forage maize.

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