Sorghum halepense (johnsongrass) is a rhizomatous, polyploidy, monocot summer crop weed. It is predominantly self-pollinated and reproduces by seeds and rhizomes. It has recently evolved resistance to acetyl-coenzyme A carboxylase (ACCase) inhibiting herbicides in Italy infesting dicot crops, mainly soybean and tomato. Four resistant (R) populations were sampled in Northern Italy from 2005 to 2007. Molecular analysis confirmed that in all of them a single amino acid substitution Ile-2041-Asn had occurred in the ACCase gene (Pignata et al., 2008, Scarabel and Sattin, 2010). Possible fitness costs associated to the mutation Ile-2041-Asp in ACCase gene were evaluated in a two-year outdoor pot-experiment: first year plants were grown from rhizomes and second year from seeds. Samples from two susceptible (S) populations were included in the experiment. Rhizome buds for the first experiment and seedlings for the second experiment were planted in big pots containing silty-loam soil and placed in semi-controlled environmental. Five harvests were carried out for each experiment during the plants life cycle. At harvest dry weight of different plant parts (shoot, panicles and seeds, and belowground material divided into rhizomes and roots), height, no. of tillers and panicles were recorded. Classical growth analysis and ANOVA (only for the final harvest) were performed for the main features. Genomic DNA was extracted from each plant with the CTAB method and analysed through a 2041-CAPS (Cleaved Amplified Polymorphic Sequence) method. Parameters calculated using classical growth analysis, including final total weight, did not show significant differences between S and R populations. Whereas significant differences were recorded for the percentage of roots and for the percentage of seeds on the total weight. Furthermore, the rhizome/panicle weight ratio was statistically different; this is mainly due to the significantly lower panicle production of the R populations, with the S populations showing values about 50% and 25% higher in the first and second experiment, respectively. ACCase resistant population seem to have a different pattern of biomass allocation between above and below ground plant parts.
Growth analysis and fitness of ACCase-inhibitors resistant Sorghum halepense with a Ile-2041-Asp mutation
Panozzo S;Sattin M
2011
Abstract
Sorghum halepense (johnsongrass) is a rhizomatous, polyploidy, monocot summer crop weed. It is predominantly self-pollinated and reproduces by seeds and rhizomes. It has recently evolved resistance to acetyl-coenzyme A carboxylase (ACCase) inhibiting herbicides in Italy infesting dicot crops, mainly soybean and tomato. Four resistant (R) populations were sampled in Northern Italy from 2005 to 2007. Molecular analysis confirmed that in all of them a single amino acid substitution Ile-2041-Asn had occurred in the ACCase gene (Pignata et al., 2008, Scarabel and Sattin, 2010). Possible fitness costs associated to the mutation Ile-2041-Asp in ACCase gene were evaluated in a two-year outdoor pot-experiment: first year plants were grown from rhizomes and second year from seeds. Samples from two susceptible (S) populations were included in the experiment. Rhizome buds for the first experiment and seedlings for the second experiment were planted in big pots containing silty-loam soil and placed in semi-controlled environmental. Five harvests were carried out for each experiment during the plants life cycle. At harvest dry weight of different plant parts (shoot, panicles and seeds, and belowground material divided into rhizomes and roots), height, no. of tillers and panicles were recorded. Classical growth analysis and ANOVA (only for the final harvest) were performed for the main features. Genomic DNA was extracted from each plant with the CTAB method and analysed through a 2041-CAPS (Cleaved Amplified Polymorphic Sequence) method. Parameters calculated using classical growth analysis, including final total weight, did not show significant differences between S and R populations. Whereas significant differences were recorded for the percentage of roots and for the percentage of seeds on the total weight. Furthermore, the rhizome/panicle weight ratio was statistically different; this is mainly due to the significantly lower panicle production of the R populations, with the S populations showing values about 50% and 25% higher in the first and second experiment, respectively. ACCase resistant population seem to have a different pattern of biomass allocation between above and below ground plant parts.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
