[Estimation of soil moisture and organic matter content in saline alkali farmland by using CARS algorithm combined with covariates].

Rapid acquisition of the data of soil moisture content (SMC) and soil organic matter (SOM) content is crucial for the improvement and utilization of saline alkali farmland soil. Based on field measurements of hyperspectral reflectance and soil properties of farmland soil in the Hetao Plain, we used a competitive adaptive reweighted sampling algorithm (CARS) to screen sensitive bands after transforming the original spectral reflectance (Ref) into a standard normal variable (SNV). Strategies Ⅰ, Ⅱ, and Ⅲ were used to model the input variables of Ref, Ref SNV, Ref-SNV+ soil covariate (SC), and digital elevation model (DEM).

Estimation of soil water and organic matter content in medium and low yield fields of Ningxia Yellow River Irrigation area based on hyperspectral information.

Accurately obtaining soil water and organic matter content is of great significance for improving soil qua-lity in croplands with medium to low yield. We explored the estimation effect of fractional order differentiation (FOD) combined with different spectral indices on soil water and organic matter content in medium and low yield croplands of Ningxia Yellow River Irrigation Area. After root mean square transformation of field measured hyperspectral reflectance, we used 0-2 FOD (with a step length of 0.

[Effects of different spectra types on the accuracy and correction of soil salt content inversion in Yinchuan Plain, China].

Soil salinization is one of key drivers for the degradation of soil quality and yield in arable land. To accurately and quickly evaluate soil salt content in Yinchuan Plain, field and indoor hyperspectral data were processed with first order differential (FDR) transformation, then the feature bands were identified by stepwise regression (SR). Partial least squares regression (PLSR) and support vector machines (SVM) were used to build models, which were verified to figure out the optimal hyperspectral type for the study area.

Cytogenetic and genomic organization analyses of chloroplast DNA invasions in the nuclear genome of Asparagus officinalis L. provides signatures of evolutionary complexity and informativity in sex chromosome evolution.

Background: The transfer of chloroplast DNA into nuclear genome is a common process in plants. These transfers form nuclear integrants of plastid DNAs (NUPTs), which are thought to be driving forces in genome evolution, including sex chromosome evolution. In this study, NUPTs in the genome of a dioecious plant Asparagus officinalis L.

The application of MutMap in forward genetic studies based on whole-genome sequencing.

Classical forward genetic analysis relies on construction of complicated progeny populations and development of many molecular markers for linkage analysis in genetic mapping, which is both time- and cost-consuming. The recently developed MutMap is a new forward genetic approach based on high-throughput next-generation sequencing technologies. It is more efficient and affordable than traditional methods.

[Spectral reflectance characteristics and modeling of typical Takyr Solonetzs water content].

Based on the analysis of the spectral reflectance of the typical Takyr Solonetzs soil in Ningxia, the relationship of soil water content and spectral reflectance was determined, and a quantitative model for the prediction of soil water content was constructed. The results showed that soil spectral reflectance decreased with the increasing soil water content when it was below the water holding capacity but increased with the increasing soil water content when it was higher than the water holding capacity. Soil water content presented significantly negative correlation with original reflectance (r), smooth reflectance (R), logarithm of reflectance (IgR), and positive correlation with the reciprocal of R and logarithm of reciprocal [lg (1/R)].

[Impacts of different alkaline soil on canopy spectral characteristics of overlying vegetation].

The relationship between alkalinity and pH of the soil, reflectance spectra and red-edge parameters of the sunflower canopy in different growth periods under different alkalinity soil were analyzed, respectively. The results showed that the spectral reflectance of the sunflower canopy in different stage under different alkalinity soil is the same as the spectral reflectance characters of the other greenery canopy. Along with the advancement of the sunflower growth period, sunflower canopy spectral reflectance increases gradually at different stages, the spectral reflectance is higher at flowering stage than 7-leaf stage and budding stage, and there exists a high reflection peak at 809nm at flowering period.