ABSTRACT
This study, about RPW and date palms, is under the scope of date palm bioecology and nutrition (nutritional ecology) which includes the integration of several areas of research such as date palm biochemistry, genetics, and RPW infestation behavior through various date palm cultivars. Date palm (Phoenix dactylifera L.; Arecaceae) production is under threat from the red palm weevil (RPW), Rhynchophorus ferrugineus Oliver. A better understanding of genetic diversity within date palm cultivars can be useful for its implementation within the insect IPM program in the future. Three indices, namely simple-sequence repeats (SSR) markers to elucidate genetic diversity, chemical components, and a natural infestation index of RPW, were used to evaluate the resistant or susceptible date palm cultivars in Qassim. Based on a field survey of RPW infestation within 79 date palm farms involving 11 cultivars at Qassim, the sensitivity and resistance cultivars were determined. The resistant date palm cultivars were Nabtat Ali, Shakrah, red Sukary, and um Kobar which had the lowest degree of RPW abundance %. Values of the essential minerals, nitrogen, phosphorus, potassium, and calcium within the date palm cultivars were also estimated. RPW abundance % was negatively correlated with the calcium content of date palm cultivars. The principal component analysis (PCA) revealed that the calcium content and RPW abundance % were highly affected by the cultivars. SSR markers of the date palm cluster tree divided genotypes into two main groups at similarity coefficients between 0.56 and 0.91. The 1st group included; Nabtet Ali, Red Sukary, Um Kobar, and Shakrah with similarity coefficients between 0.56, this group was the most resistant cultivars. Therefore, SSR markers were able to characterize and resolve genetic diversity in date palm cultivars for RPW resistance. When SSR markers coupled with higher calcium (Ca) content can efficiently replace indices in characterizing resistant date-palm genotypes with a high confidence level. Integration between date palm genetic diversity, chemical structures, and RPW infestations rates promoted the understanding of the interplay between the diversity of RPW management (short-time scale), and the resistance genes, plant nutrition, and dynamics of the diversity of RPW through domestication and diversification (long-timescale). Therefore, our results may lead to a change in RPW control strategies by switching to using safe alternative pesticide control methods (Resistant cultivars of date palm), which are underestimated and may reveal the impact of low-cost, but highly effective agricultural practices in the field of date production in the world. Understanding the genetic structure and calcium content of date palm cultivars mechanisms could help to predict date palm resistance against RPW populations in the new IPM strategy in RPW control.
Subject(s)
Moths , Phoeniceae , Weevils , Animals , Phoeniceae/genetics , Weevils/genetics , Calcium , Genetic Variation/geneticsABSTRACT
This study, about RPW and date palms, is under the scope of date palm bioecology and nutrition (nutritional ecology) which includes the integration of several areas of research such as date palm biochemistry, genetics, and RPW infestation behavior through various date palm cultivars. Date palm (Phoenix dactylifera L.; Arecaceae) production is under threat from the red palm weevil (RPW), Rhynchophorus ferrugineus Oliver. A better understanding of genetic diversity within date palm cultivars can be useful for its implementation within the insect IPM program in the future. Three indices, namely simple-sequence repeats (SSR) markers to elucidate genetic diversity, chemical components, and a natural infestation index of RPW, were used to evaluate the resistant or susceptible date palm cultivars in Qassim. Based on a field survey of RPW infestation within 79 date palm farms involving 11 cultivars at Qassim, the sensitivity and resistance cultivars were determined. The resistant date palm cultivars were Nabtat Ali, Shakrah, red Sukary, and um Kobar which had the lowest degree of RPW abundance %. Values of the essential minerals, nitrogen, phosphorus, potassium, and calcium within the date palm cultivars were also estimated. RPW abundance % was negatively correlated with the calcium content of date palm cultivars. The principal component analysis (PCA) revealed that the calcium content and RPW abundance % were highly affected by the cultivars. SSR markers of the date palm cluster tree divided genotypes into two main groups at similarity coefficients between 0.56 and 0.91. The 1st group included; Nabtet Ali, Red Sukary, Um Kobar, and Shakrah with similarity coefficients between 0.56, this group was the most resistant cultivars. Therefore, SSR markers were able to characterize and resolve genetic diversity in date palm cultivars for RPW resistance. When SSR markers coupled with higher calcium (Ca) content can efficiently replace indices in characterizing resistant date-palm genotypes with a high confidence level. Integration between date palm genetic diversity, chemical structures, and RPW infestations rates promoted the understanding of the interplay between the diversity of RPW management (short-time scale), and the resistance genes, plant nutrition, and dynamics of the diversity of RPW through domestication and diversification (long-timescale). Therefore, our results may lead to a change in RPW control strategies by switching to using safe alternative pesticide control methods (Resistant cultivars of date palm), which are underestimated and may reveal the impact of low-cost, but highly effective agricultural practices in the field of date production in the world. Understanding the genetic structure and calcium content of date palm cultivars mechanisms could help to predict date palm resistance against RPW populations in the new IPM strategy in RPW control.
Este estudo, sobre RPW e tamareiras, está no âmbito da bioecologia e nutrição da tamareira (ecologia nutricional) que inclui a integração de várias áreas de pesquisa, como bioquímica da tamareira, genética e comportamento de infestação de RPW através de vários cultivares de tamareira. A produção da tamareira (Phoenix dactylifera L.; Arecaceae) está ameaçada pelo gorgulho vermelho da palmeira (RPW), Rhynchophorus ferrugineus Oliver. A compreensão mais aprofundada da diversidade genética dentro dos cultivares de tamareiras pode ser útil para sua implementação no futuro programa de MIP de insetos. Três índices, ou seja, marcadores de sequência simples (SSR) para elucidar a diversidade genética, componentes químicos e um índice de infestação natural de RPW, foram utilizados para avaliar as cultivares de tamareiras resistentes ou suscetíveis em Qassim. Com base em uma pesquisa de campo da infestação de RPW em 79 fazendas de tamareiras envolvendo 11 cultivares em Qassim, as cultivares de sensibilidade e resistência foram determinadas. As cultivares de tamareiras resistentes foram Nabtat Ali, Shakrah, red Sukary e um Kobar, que apresentaram o menor grau de abundância de RPW. Também foram estimados os valores dos minerais essenciais, nitrogênio, fósforo, potássio e cálcio nas cultivares de tamareira. A porcentagem de abundância de RPW correlacionou-se negativamente com o teor de cálcio das cultivares de tamareira. A análise de componentes principais (PCA) revelou que o teor de cálcio e a abundância de RPW % foram altamente afetados pelas cultivares. Marcadores SSR da tamareira dividiram os genótipos em dois grupos principais com coeficientes de similaridade entre 0,56 e 0,91. O 1º grupo incluiu; Nabtet Ali, Red Sukary, Um Kobar e Shakrah com coeficientes de similaridade entre 0,56, este grupo foi o de cultivares mais resistentes. Portanto, os marcadores SSR foram capazes de caracterizar e resolver a diversidade genética em cultivares de tamareiras para resistência a RPW. Quando os marcadores SSR associados ao maior teor de cálcio (Ca) podem substituir com eficiência os índices na caracterização de genótipos de tamareiras resistentes com alto nível de confiança. A integração entre diversidade genética da tamareira, estruturas químicas e taxas de infestação de RPW promoveu a compreensão da interação entre a diversidade de manejo de RPW (escala de tempo curto) e os genes de resistência, nutrição de plantas e dinâmica da diversidade de RPW por meio da domesticação e diversificação (longo prazo). Portanto, nossos resultados podem levar a uma mudança nas estratégias de controle de RPW, passando a usar métodos alternativos seguros de controle de pesticidas (cultivares resistentes de tamareira), sendo subestimados e podem revelar o impacto de práticas agrícolas de baixo custo, mas altamente eficazes no campo de produção de tâmaras no mundo. Compreender a estrutura genética e o teor de cálcio dos mecanismos dos cultivares de tamareira pode ajudar a prever a resistência da tamareira contra populações de RPW na nova estratégia de IPM no controle de RPW.