Categorization of wheat genotypes for phosphorus efficiency

Abstract

Production of phosphorus efficient crop cultivars can increase food productivity and decrease environmental pollution. Categorization of existing germplasm is a prerequisite to develop P efficient crop cultivars. For first experiment, 30 wheat genotypes were grown in hydroponics with two P levels (i.e., deficit, 20 μm KH2PO4 and adequate, 200 μm KH2PO4). Genotypes differed significantly for various P efficiency parameters. Two genotypes (Dirk and Bhakkar-02) showed < 25% decrease in growth at P deficiency. Genotype Seher-06 proved to be inefficient. Twelve selected genotypes based on the first experiment were sown in soil with two P levels (0 and 30 mg P kg-1) till maturity. As expected, genotypes differed for grain yield at both P levels. The efficient cultivars selected on the basis of both absolute and relative dry matter production at both P levels such as Dirk. Genotypes were grouped into three, four and nine classes on the basis of various parameters for P efficiency as proposed by different researchers. Most genotypes behaved in a similar fashion by different categorization methods and also at different P supply. The method to categorize the genotypes into three classes and plotting them into 9 classes proposed by Gill and his coworkers, is the best to differentiate the minor differences in genotypes. At least three different parameters at both P regimes should be used. The parameters may vary as per objectives of the study and/or growth conditions.

Characterizing Lentil Germplasm for Zinc Biofortification and High Grain Output

“…Several researchers documented the Zn application rates of 5-25 kg ha −1 to correct the Zn deficiency (Cakmak 2008b;Abid et al 2013;Zhao et al 2014;Cakmak and Kutman 2018). Moreover, high levels of inorganic phosphorus adversely affect the Zn availability (Perez-Novo et al 2011 LGZn-LGY (Bilal et al 2018) in lentil genotypes (Fig. 3) as already investigated by researchers (Marschner and Cakmak 1986;Erdal et al 2002;Thavarajah et al 2009), and maximum value of grain phytate concentration was observed where no Zn was applied.…”

“…Categorisation of lentil genotypes was done by using index scores of 1, 2 and 3 for low, medium and high scoring genotypes, respectively. Genotypic classification is made based on their performance of applied Zn with respect to control by calculating the population mean (μ) and standard deviation (SD) of desired parameters (Aziz et al 2011;Bilal et al 2018). Lentil genotypes are allocated as high if their population mean is greater than μ + SD, medium if their population mean is between μ + SD to μ − SD and low if genotype mean is less than μ − SD.…”

Genotypic Variation in Cotton Genotypes for Phosphorus-Use Efficiency

“…P-use efficiency is comprised of two major components, i.e., P uptake and utilization efficiency. P-uptake efficiency is the capacity of plants to uptake P from the soils while how efficiently the plants utilize the absorbed P is utilization efficiency [18]. The P-use efficiency among cotton genotypes varies with traits and the method of screening.…”

“…Therefore, different scientists have proposed different criteria of screening genotypes for P-use efficiency under P-deficient conditions, such as total P uptake [19], dry matter produced per unit of P applied [20], and the ratio of physiologically active P to total P uptake [21]. Besides this, care should be taken in comparing the genetic and physiological components to measure P efficiency, as different methods may lead to different P efficiency under the same condition [18]. Some researchers have focused on the importance of root architecture for P efficiency under deficient P conditions [19,22].…”

“…Some researchers have focused on the importance of root architecture for P efficiency under deficient P conditions [19,22]. However, both root and shoot should be taken into account for studying P efficiency under low P conditions as roots help in P acquisition and shoots in P utilization [18]. Many researchers have found that an extensive root system under low P conditions could enable the plant to improve root volume to explore and uptake more P [17,23,24].…”