<b>Phosphorus uptake and use efficiency of different cotton cultivars in savannah soil (Acrisol)

Abstract

ABSTRACT. Low soil phosphorus (P) is a limiting factor for plant growth in the Brazilian savannah, where P diffuses slowly and has a high fixation rate in soil (as Al-P and Fe-P). In this study, we investigated the variation in P uptake by different cotton cultivars grown in savannah soil. We conducted a greenhouse experiment using a fully factorial 2 x 17 randomized design with two P treatments (low P = 20 mg kg ) and 17 cotton cultivars. The plants were potted in Acrisol soil labeled with radioisotope 32 P. There was genetic variation in the P use efficiency among the cotton cultivars. The P treatments significantly influenced the dry weight of shoots (DWS), P accumulation, the specific activity of 32 P, and the L-value (both the standardized and L-values discounted the P present in the cottonseed). Hierarchical clustering analysis classified the cotton cultivars into distinct, internally homogeneous clusters. Our results suggest that cotton cultivars could be selected to maximize P absorption efficiency in conditions of low plant-available P. The cultivars FMT 523, FM 910 and CNPA GO 2043 were the most responsive to P fertilization, while Barbadense 01, FM 966LL, IPR Jataí, BRS Aroeira and BRS Buriti were most efficient at absorbing plant-available P. Keywords:32 P activity, G. barbadense, G. hirsutum, Brazilian Cerrado.Eficiência de absorção e utilização de fósforo por cultivares de algodão em um solo de Cerrado (Latossolo Vermelho Amarelo) RESUMO. A baixa disponibilidade de fósforo (P) é um fator limitante para o crescimento de plantas no Cerrado Brasileiro, onde a difusão do P é baixa e o solo tem grande capacidade de fixação do P por óxidos de ferro e alumínio. Nesse estudo foi investigado a variação da absorção de P por diferentes cultivares de algodão cultivados em solo proveniente da região do Cerrado. Foi conduzido um experimento de casa de vegetação em delineamento inteiramente casualizado em esquema fatorial 2 x 17, dois tratamento com P (baixo P = 20 mg kg -1 e alto P = 120 mg kg -1 ) e 17 cultivares de algodão. As plantas foram cultivadas em vasos com um solo marcado com o radioisótopo 32 P. Houve variação genética para eficiência uso de P entre cultivares de algodão. O tratamentos com P influenciaram significativamente a matéria seca da parte aérea, acúmulo de P, atividade específica do 32 P, valor L e valor L descontando o P proveniente das sementes. A análise multivariada classificou os cultivares de algodão em grupos distintos e homogêneos internamente. Os resultados desse trabalho sugerem que pode-se selecionar cultivares de algodão mais eficientes em absorver e utilizar P em solos com baixa disponibilidade de P para as plantas. Os cultivares FMT 523, FM 910 e CNPA GO 2043 foram os mais responsivos a adubação fosfatada, enquanto que os cultivares Barbadense 01, FM 966LL, IPR Jataí, BRS Aroeira e BRS Buriti foram os mais eficientes na utilização de P.Palavras-chave: atividade do radioisótopo 32 P, G. barbadense, G. hirsutum, Cerrado.

Phosphorus Efficiency in Brazilian Soybean Cultivars

“…As the root system was not analysed for the L value and total P in the present study, it was impossible to prove this assumption. Similar results were found among cotton cultivars [27], but not among wheat cultivars [8], suggesting that perhaps monocotyledonous and dicotyledonous plants may differ regarding the fate of the absorbed P. Total P had a significant and negative correlation with P use efficiency, indicating that greater P utilisation efficiency occurs with lower amount of P in the shoot. The fact that P use efficiency is positively correlated with shoot dry mass and negatively correlated with total P suggests that the genotypes with greater P use efficiency are most adapted to soil conditions with low P, as they are capable of producing biomass with a lower P amount in the shoot.…”

“…Fernandes and Muraoka [5] used the specific activity to select seven maize hybrids that are very efficient to absorb P in Brazilian savanna soil. The L value-seed was used by Silva et al [8] to identify wheat cultivars with greater efficiency in the P uptake, and by Marcante et al [27] who selected cotton cultivars using this characteristic. The L value-seed was also used [28,29] to classify rice and bean cultivars based on P uptake efficiency.…”

Research Article Morphological, biochemical and molecular characterization of sorghum (<i>Sorghum</i> <i>bicolor</i>) genotypes contrasting for phosphate-use efficiency

“…Higher plants have developed several strategies to deal with Pi deprivation by activating adaptive responses to enhance P assimilation to maintain the Pi homeostasis (Raghothama, 2000;Rai et al, 2015). Inter-and intra-specific variations in the ability of plants to grow under Pi-limiting conditions have been reported earlier for several agronomic crop species (Gahoonia and Nielsen, 2004;Aziz et al, 2014;Leiser et al, 2015;Marcante et al, 2016). Researchers at the Embrapa, Brazilian Enterprise for Agricultural Research have pursued the goal of validating sorghum cultivars adapted to low levels of available P in the acidic soil of the Cerrado for the last three decades.…”

“…Many studies have been made to try to understand the gene regulatory network involved in Pi uptake by plants and the identification of genes and signaling cascades involved in plant responses to Pi deficiency (Muchhal and Hammond et al, 2004;Gu et al, 2016). Also, concurrently, efforts have been directed towards elucidation of the complex molecular mechanisms underlying genotype differences in Pi uptake from Pi-deficient soils (Hammond et al, 2004;Leiser et al, 2015;Marcante et al, 2016;Schneider and Lynch, 2016;Vasconcelos et al, 2018).…”

“…Thus, the differences in Pi-use efficiency among cultivars are due to the mode of action and between the mechanisms mentioned above (Aziz et al, 2014;Marcante et al, 2016). In our study, we focused on evaluating the usefulness of aerenchyma formation, plant dry weight matter, acid phosphatase enzyme (APA), and the expression of phosphate transporter genes for characterizing contrasting Pi-efficient and Pi-inefficient sorghum genotypes.…”