Safflower represents an important oil crop internationally and may have a production potential under low input conditions, but its putatively high phosphorous use efficiency is not sustained. This study aims to direct...Safflower represents an important oil crop internationally and may have a production potential under low input conditions, but its putatively high phosphorous use efficiency is not sustained. This study aims to directly compare safflower with sunflower in terms of phosphorus use efficiency in nutrient solution under controlled conditions. Growth of both species responded strongly to increasing P supply. Safflower recovers less proportion of added P than sunflower. External P requirement （（g P supply （100 g dry matter （DM） produced）~） was higher in safflower than sunflower. The efficiency of the crops for DM production based on accumulated P （mg P potl, efficiency ratio）, and P concentration in DM （（mg P （g DM）＇I）, utilization index） were interpreted using Michaelis-Menten kinetics as growth response curves. Accordingly, Km constant was lower in sunflower compared to safflower in terms of utilization index, but both were similar in terms of efficiency ratio. High Km constant in safflower in terms of utilization index indicates the high P concentration in tissues to produce 50% of potential maximum DM, consequently less efficient crop. Utilization efficiency contributed more than uptake efficiency in overall PUE in the efficient cultivar and could be the cause of its superiority in PUE. It can be concluded that safflower has a high requirement for P with respect to growth, sunflower is more efficient in terms of uptake and utilization of P at optimal and sub-optimal P supplies indicating that safflower can not be considered a low nutrient input crop compared to sunflower with respect to phosphorus.展开更多
Rapeseed is one of the major oil crops in China and it is very sensitive to climate change.The Yangtze River Basin is the main rapeseed production area in China.Therefore,a better understanding of the impact of climat...Rapeseed is one of the major oil crops in China and it is very sensitive to climate change.The Yangtze River Basin is the main rapeseed production area in China.Therefore,a better understanding of the impact of climate change on rapeseed production in the basin is of both scientific and practical importance to Chinese oil industry and food security.In this study,based on climate data from 5 General Circulation Models(GCMs) with 4 representative concentration pathways(RCPs) in 2011–2040(2020 s),2041–2070(2050 s) and 2071–2100(2080 s),we assessed the changes in rapeseed production potential between the baseline climatology of 1981–2010 and the future climatology of the 2020 s,2050 s,and 2080 s,respectively.The key modelling tool – the AEZ model – was updated and validated based on the observation records of 10 representative sites in the basin.Our simulations revealed that:(1) the uncertainty of the impact of climate change on rapeseed production increases with time;(2) in the middle of this century(2050 s),total rapeseed production would increase significantly;(3) the average production potential increase in the 2050 s for the upper,middle and lower reaches of the Yangtze River Basin is 0.939,1.639 and 0.339 million tons respectively;(4) areas showing most significant increases in production include southern Shaanxi,central and eastern Hubei,northern Hunan,central Anhui and eastern Jiangsu.展开更多
文摘Safflower represents an important oil crop internationally and may have a production potential under low input conditions, but its putatively high phosphorous use efficiency is not sustained. This study aims to directly compare safflower with sunflower in terms of phosphorus use efficiency in nutrient solution under controlled conditions. Growth of both species responded strongly to increasing P supply. Safflower recovers less proportion of added P than sunflower. External P requirement （（g P supply （100 g dry matter （DM） produced）~） was higher in safflower than sunflower. The efficiency of the crops for DM production based on accumulated P （mg P potl, efficiency ratio）, and P concentration in DM （（mg P （g DM）＇I）, utilization index） were interpreted using Michaelis-Menten kinetics as growth response curves. Accordingly, Km constant was lower in sunflower compared to safflower in terms of utilization index, but both were similar in terms of efficiency ratio. High Km constant in safflower in terms of utilization index indicates the high P concentration in tissues to produce 50% of potential maximum DM, consequently less efficient crop. Utilization efficiency contributed more than uptake efficiency in overall PUE in the efficient cultivar and could be the cause of its superiority in PUE. It can be concluded that safflower has a high requirement for P with respect to growth, sunflower is more efficient in terms of uptake and utilization of P at optimal and sub-optimal P supplies indicating that safflower can not be considered a low nutrient input crop compared to sunflower with respect to phosphorus.
基金National Natural Science Foundation of China,No.41671113,No.51761135024,No.41601049,No.41475040China’s National Science&Technology Pillar Program,No.2016YFC0502702
文摘Rapeseed is one of the major oil crops in China and it is very sensitive to climate change.The Yangtze River Basin is the main rapeseed production area in China.Therefore,a better understanding of the impact of climate change on rapeseed production in the basin is of both scientific and practical importance to Chinese oil industry and food security.In this study,based on climate data from 5 General Circulation Models(GCMs) with 4 representative concentration pathways(RCPs) in 2011–2040(2020 s),2041–2070(2050 s) and 2071–2100(2080 s),we assessed the changes in rapeseed production potential between the baseline climatology of 1981–2010 and the future climatology of the 2020 s,2050 s,and 2080 s,respectively.The key modelling tool – the AEZ model – was updated and validated based on the observation records of 10 representative sites in the basin.Our simulations revealed that:(1) the uncertainty of the impact of climate change on rapeseed production increases with time;(2) in the middle of this century(2050 s),total rapeseed production would increase significantly;(3) the average production potential increase in the 2050 s for the upper,middle and lower reaches of the Yangtze River Basin is 0.939,1.639 and 0.339 million tons respectively;(4) areas showing most significant increases in production include southern Shaanxi,central and eastern Hubei,northern Hunan,central Anhui and eastern Jiangsu.
