Aroma volatile characterisation and gene expression analysis during fruit development and ripening of five pear (<i>Pyrus L.</i>) species

Bartlett, Hongnanguo, Korla Xiangli, Dangshansuli and Housui are representative cultivars from the five cultivated pear species that were chosen to identify aromatic compounds in fruit during developmental, mature and storage periods. We explored the expression levels of aroma formation-related genes during developmental and storage periods. The concentrations of the aromatic compounds first decreased, then increased in all five cultivars. For the climacteric pears, Bartlett and Hongnanguo, the increase continued to optimal sensory quality (OSQ), whereas those for the non-climacteric pears, Korla Xiangli, Dangshansuli and Housui decreased. Aldehydes contributing the 'green' odour and 1,4-benzoquinone were the primary components during early and middle developmental periods. Esters contributing the 'fruity' and 'sweet' odour, were the primary components in Bartlett, Hongnanguo and Korla Xiangli fruits during storage and at OSQ. Methyl- and ethyl-(E, Z)-2,4-decadienoate (pear-like odour), ethyl caproate (liquor odour), and hexyl acetate (fruity odour) were the key characteristic odorants in mature pear fruits of Bartlett, Hongnanguo and Korla Xiangli, respectively. Alcohol dehydrogenase (PbrADH-1 and PbrADH-2) and lipoxygenase (PbrLOX3) might participate in the formation of C6 and C9 volatile aldehydes and alcohols. The aroma content and volatiles of pear fruits during development and storage probably revealed a common pattern.</p

Biochar derived from corn straw affected availability and distribution of soil nutrients and cotton yield

<div><p>Biochar application as a soil amendment has been proposed as a strategy to improve soil fertility and increase crop yields. However, the effects of successive biochar applications on cotton yields and nutrient distribution in soil are not well documented. A three-year field study was conducted to investigate the effects of successive biochar applications at different rates on cotton yield and on the soil nutrient distribution in the 0–100 cm soil profile. Biochar was applied at 0, 5, 10, and 20 t ha^-1 (expressed as Control, BC5, BC10, and BC20, respectively) for each cotton season, with identical doses of chemical fertilizers. Biochar enhanced the cotton lint yield by 8.0–15.8%, 9.3–13.9%, and 9.2–21.9% in 2013, 2014, and 2015, respectively, and high levels of biochar application achieved high cotton yields each year. Leaching of soil nitrate was reduced, while the pH values, soil organic carbon, total nitrogen (N), and available K content of the 0–20 cm soil layer were increased in 2014 and 2015. However, the changes in the soil available P content were less substantial. This study suggests that successive biochar amendments have the potential to enhance cotton productivity and soil fertility while reducing nitrate leaching.</p></div

Soil pH values after cotton harvested in 2013, 2014 and 2015.

<p>Soil pH values after cotton harvested in 2013, 2014 and 2015.</p

Influence of biochar application on crop yields and soil properties based on the literatures.

<p>Influence of biochar application on crop yields and soil properties based on the literatures.</p

Soil NH₄⁺−Nin 0–100 cm soil after cotton harvested in 2013, 2014and 2015.

<p>Soil NH₄⁺−Nin 0–100 cm soil after cotton harvested in 2013, 2014and 2015.</p

Soil total Nin 0–100 cm soil after cotton harvested in 2013, 2014and 2015.

<p>Soil total Nin 0–100 cm soil after cotton harvested in 2013, 2014and 2015.</p

Soil available K contents after cotton harvested in 2013, 2014 and 2015 (mg kg^-1).

<p>Soil available K contents after cotton harvested in 2013, 2014 and 2015 (mg kg^-1).</p

Fiber quality in response to biochar application at different rates.

<p>Fiber quality in response to biochar application at different rates.</p

Soil available P contents after cotton harvested in 2013, 2014 and 2015 (mg kg^-1).

<p>Soil available P contents after cotton harvested in 2013, 2014 and 2015 (mg kg^-1).</p

Cotton yield and yield components in response to biochar application at the rate of 0, 5, 10 or 20 t ha⁻¹ in 2013, 2014and 2015.

<p>Cotton yield and yield components in response to biochar application at the rate of 0, 5, 10 or 20 t ha⁻¹ in 2013, 2014and 2015.</p