Water Deficit-Responsive QTLs for Cell Wall Degradability and Composition in Maize at Silage Stage

The use of lignocellulosic biomass for animal feed or biorefinery requires the optimization of its degradability. Moreover, biomass crops need to be better adapted to the changing climate and in particular to periods of drought. Although the negative impact of water deficit on biomass yield has often been mentioned, its impact on biomass quality has only been recently reported in a few species. In the present study, we combined the mapping power of a maize recombinant inbred line population with robust near infrared spectroscopy predictive equations to track the response to water deficit of traits associated with biomass quality. The population was cultivated under two contrasted water regimes over 3 consecutive years in the south of France and harvested at silage stage. We showed that cell wall degradability and β-O-4-linked H lignin subunits were increased in response to water deficit, while lignin and p-coumaric acid contents were reduced. A mixed linear model was fitted to map quantitative trait loci (QTLs) for agronomical and cell wall-related traits. These QTLs were categorized as “constitutive” (QTL with an effect whatever the irrigation condition) or “responsive” (QTL involved in the response to water deficit) QTLs. Fifteen clusters of QTLs encompassed more than two third of the 213 constitutive QTLs and 13 clusters encompassed more than 60% of the 149 responsive QTLs. Interestingly, we showed that only half of the responsive QTLs co-localized with constitutive and yield QTLs, suggesting that specific genetic factors support biomass quality response to water deficit. Overall, our results demonstrate that water deficit favors cell wall degradability and that breeding of varieties that reconcile improved drought-tolerance and biomass degradability is possible

Inheritance of oleic acid content of F1 seed in a complete diallel cross between seven sunflower lines

International audienc

Evaluation of parameters accounting for Phomopsis resistance using natural infection and artificial inoculation on recombinant inbred lines from a cross between susceptible and resistant sunflower

International audienc

Resistance to stem canker /phomopsis (Diaporthe helianthi Munt-Cvet et al.) in relation to introgressions from wild species in sunflower (Helianthus annuus L.)

International audienc

Interspecific crosses sunflower x perennial Helianthus: hybridization failure to normal crosses

International audienc

Combined mapping of DALP and AFLP markers in cultivated sunflower using F9 recombinant inbred lines

DOI: 10.1007/s00122-002-1087-xInternational audienc

Energy values of registered corn forage hybrids in France over the last 20 years rose in a context of maintained yield increase

The cultivation of corn silage has developed in France since the 1970s to reach 1.5 million of hectares nowadays. Since 1998, a feeding value criterion (namely UFL for “Unité Fourrage Laitière”) has been taken into account to register forage varieties in the French forage maize hybrids catalog in addition to other criteria related to plant agronomical performances such as yield, earliness and lodging resistance. It is frequently stated that the improvement of plant’s agronomic performances would led to a decline in forage energy value. Decline of “Unité Fourrage Laitière” values has been repeatedly reported and the expected increase was not yet visible in 2002. In the present study, a set 47 early and mid-early hybrids commercialized in France between 1958 and 2015 has been cultivated in 3 locations in France. “Unité Fourrage Laitière” values and yield have been estimated in order to shed light on the evolution of feeding value criteria during this period and to conclude on the evolution of “Unité Fourrage Laitière” values since the introduction of this criterion for registration. Results obtained in our study demonstrated a recent rise in “Unité Fourrage Laitière” value in a context of strong yield increase. This increase was not necessarily attributable to high cob proportion in the harvested silage. Breeder’s work since the 2000’s has succeeded to offer hybrids that recover “Unité Fourrage Laitière” values similar to the ones of hybrids from the 1960’s (Royal, 1960, 91 UFL/100 kg DM). We propose to accentuate this effort targeting the enhancement of lignocellulosic cell wall digestibility to breed for future forage maize hybrids

Effect of recurrent selection on agronomic traits for several sunflower gene pools

International audienc

Maintenance, evaluation and use of a wild Helianthus collection at INRA Montpellier

International audienc