Using crop growth model stress covariates and AMMI decomposition to better predict genotype-by-environment interactions.

KEY MESSAGE: We propose new methods to predict genotype × environment interaction by selecting relevant environmental covariates and using an AMMI decomposition of the interaction. Farmers are asked to produce more efficiently and to reduce their inputs in the context of climate change. They have to face more and more limiting factors that can combine in numerous stress scenarios. One solution to this challenge is to develop varieties adapted to specific environmental stress scenarios. For this, plant breeders can use genomic predictions coupled with environmental characterization to identify promising combinations of genes in relation to stress covariates. One way to do it is to take into account the genetic similarity between varieties and the similarity between environments within a mixed model framework. Molecular markers and environmental covariates (EC) can be used to estimate relevant covariance matrices. In the present study, based on a multi-environment trial of 220 European elite winter bread wheat (Triticum aestivum L.) varieties phenotyped in 42 environments, we compared reference regression models potentially including ECs, and proposed alternative models to increase prediction accuracy. We showed that selecting a subset of ECs, and estimating covariance matrices using an AMMI decomposition to benefit from the information brought by the phenotypic records of the training set are promising approaches to better predict genotype-by-environment interactions (G × E). We found that using a different kinship for the main genetic effect and the G × E effect increased prediction accuracy. Our study also demonstrates that integrative stress indexes simulated by crop growth models are more efficient to capture G × E than climatic covariates.

Minimally invasive laparo-thoracoscopic Ivor-Lewis esophagectomy with semi-mechanical triangular anastomosis: Short-term outcomes of 114 consecutive patients.

INTRODUCTION: Several surgical teams have developed so-called minimally invasive esophagectomy techniques with the intention of decreasing post-operative complications. The goal of this report is to determine the feasibility, reproducibility, morbidity and mortality of esophagectomy and intrathoracic anastomosis via thoracoscopy. METHODS: This retrospective series included 114 consecutive non-selected patients who underwent Lewis Santy type esophagectomy between 2016 and 2020. The procedure was performed via abdominal laparoscopy, thoracoscopy with the patient in a supine position, without selective intubation, with intra-thoracic semi-mechanical triangular esophagogastric anastomosis. RESULTS: Mean patient age was 62.8years. Conversion from laparoscopy to laparotomy was required in three patients (2.6%); no patient required conversion from thoracoscopy to thoracotomy. A semi-mechanical triangular esophagogastric anastomosis was successfully performed in all patients. Median duration of hospital stay was 16 (8-116) days. Mortality was 2.6%; 34 patients (29.8%) had major complications, 55 (48%) had a respiratory complication. The leakage rate was 12.3%; most were type I. Only 5.2% required an additional procedure. There was no mortality. CONCLUSION: The analysis of this consecutive series found that this operative technique was reproducible and reliable. These results need to be confirmed by other studies. Pulmonary morbidity was high and remains the main challenge in this type of surgery.

New, simple and reliable volumetric calculation technique in incisional hernias with loss of domain.

INTRODUCTION: The management of hernias with loss of domain is a challenging problem. It has been shown that the volume of the incisional hernia/peritoneal volume ratio < 20% was a predictive factor for tension-free fascia closure, after pre-operative pneumoperitoneum preparation (Goni Moreno technique). In this study, we propose an easy, reliable and fast technique to perform volumetric calculation, by the surgeon alone. MATERIALS AND METHODS: 3D slicer software (free open-source software) was used to calculate with precision the intra-peritoneal and intra-hernia volumes, and to create a 3D reconstruction of both volumes. The measurement technique is described step by step using detailed figures and videos. RESULTS: The method was used to calculate the volumes for five consecutive patients, managed between January 2018 and March 2019. All the five patients had a ratio greater than 20% and, therefore, received a PPP program. The effectiveness of the procedure is objectified by the increase of the intraabdominal volume and the reduction of the incisional hernia/peritoneal volume ratio. The feasibility of a tension-free fascia closure was confirmed for the five patients. CONCLUSION: In addition to a standardized definition of "loss of domain", a standardized volumetric technique, easy to reproduce, needs to be adopted. Our method can be done by any surgeon with basic computer skills and radiological knowledge in an autonomous and a fast manner, thus helping to select the right technique for the right patient.

[Epidermoid bronchial cancer induced by radiotherapy]. / Cancer bronchique épidermoïde induit par la radiothérapie.

The occurrence is reported of a bronchial epidermoid cancer appearing 13 years after irradiation for an intra-thoracic paraganglioma. Four criteria are required when considering the carcinogenic effects of radiation: a documented history or irradiation, a latent period of 8 to 20 years, histological evidence of the development of a malign tumor within the irradiated zone and a different histological type from that of the primary tumor. All these criteria are satisfied in this case. The occurrence of post radiation fibrosis and the knowledge of a cancer developing in primary or secondary pulmonary fibrosis are considered in discussing carcinogenesis. Radiation induces fibrous and an oncogenic mutation which by the secretion of certain proteins, notably a growth factor, favours the development of a cancer.

Genetic analysis of dry matter and nitrogen accumulation and protein composition in wheat kernels.

The maximum rate and duration for grain dry matter (DM) and nitrogen (N) accumulation were evaluated in 194 recombinant inbred lines (RILs) from a cross between the two French wheat cultivars Récital and Renan. These cultivars were previously identified as having contrasting kinetics of grain DM and N accumulation. Grain protein composition was analysed by capillary electrophoresis (CE), which enabled quantification of the different storage protein fractions (alphabetagamma-gliadins, omega-gliadins, LMW glutenins, HMW glutenins, and each of their subunits). Correlation analyses revealed that DM and N accumulation rates were closely correlated and repeatable over several years, which was not the case for DM and N accumulation durations, and that protein composition was primarily influenced by the N accumulation rate. This was particularly true for the LMW-glutenins and the alphabetagamma-gliadins, the most abundant protein fractions. A genetic map of 254 molecular markers covering nearly 80% of the wheat genome was used for quantitative trait loci (QTL) analysis. A total of seven QTLs were found. Five QTLs were significantly associated with the kinetics of DM and N accumulation, and two of them also influenced protein composition. Two QTLs affected only the protein composition. One major QTL explained more than 70% of the total variation in HMW-GS Glu1B-x content.

Hydraulic conductance and mercury-sensitive water transport for roots of Opuntia acanthocarpa in relation to soil drying and rewetting.

Drought-induced changes in root hydraulic conductance (LP) and mercury-sensitive water transport were examined for distal (immature) and mid-root (mature) regions of Opuntia acanthocarpa. During 45 d of soil drying, LP decreased by about 67% for distal and mid-root regions. After 8 d in rewetted soil, LP recovered to 60% of its initial value for both regions. Axial xylem hydraulic conductivity was only a minor limiter of LP. Under wet conditions, HgCl2 (50 microM), which is known to block membrane water-transport channels (aquaporins), decreased LP and the radial hydraulic conductance for the stele (L(R, S)) of the distal root region by 32% and 41%, respectively; both LP and L(R, S) recovered fully after transfer to 2-mercaptoethanol (10 mM). In contrast, HgCl2 did not inhibit LP of the mid-root region under wet conditions, although it reduced L(R, S) by 41%. Under dry conditions, neither LP nor L(R, S) of the two root regions was inhibited by HgCl2. After 8 d of rewetting, HgCl2 decreased LP and L(R, S) of the distal region by 23% and 32%, respectively, but LP and L(R, S) of the mid-root region were unaltered. Changes in putative aquaporin activity accounted for about 38% of the reduction in LP in drying soil and for 61% of its recovery for the distal region 8 d after rewetting. In the stele, changes in aquaporin activity accounted for about 74% of the variable L(R, S) during drought and after rewetting. Thus, aquaporins are important for regulating water movement for roots of O. acanthocarpa.