论文部分内容阅读
At regional levels, IPCC scenarios are not helpful and uncertainties exist in thedegree of warming and may have positive or negative impacts on different crops.Therefore assessment of long-term regional trend in temperature is mandatory tounderstand potential impacts of future climates.Here, we have put a deliberate effort toanalyze the historical weather data of Jiangsu Province located at lower reaches of YRV toascertain changing trend in temperature extremes and its derived stress days and nightsduring RGP as proxy of rice sterility in this region.Asymmetric seasonal changes in dailymaximum (TMX) and minimum (TMN) temperatures resulted in reduced diurnaltemperature range (DTR) during studied period.Mean relative humidity also decreased atdifferent temporal scales, though regional variations exist.Frequency of hot nights (HN)and heatwave-B (HW-B) substantially increased in the last 20 years resulted in increasedoccurrence of severe hot days (SHD) and severe heatwave (SHW) when both TMX andTMN are higher than described critical limit.Hot nights (HN) were observed only in thesecond half (SH) of the dataset, while their intensity has been increasing with time.Episodic sterility occurs in the absence of extreme heat events, and we have herebyconfirmed the increasing trend of HNs and days with both higher TMX and TMN (SHD,severe hot days) associated with this crucial issue.Stagnant observation of TMX, hot days(HDs), and heatwave-A (HW-A) while, increasing trend of TMN, HN, (HW-B), SHD and(SHW) are main features of changing climate in the region.
Experiments aimed to study responses of crops to rising temperature are mainlyconducted under controlled cover conditions like greenhouses, open-top chamber etc.These indoor facilities cannot mimic predicted climatic conditions and can significantlyalter crop microclimate.These potential artifacts can have undesirable impacts of plantgrowth and developmental processes.Use of infrared heaters (IRH) is one of the attractivealternatives which can provide reliable and reproducible canopy wanning for differentcrops in similar way they are heated by solar radiation.As compared to warming ingreenhouses, open-top champers and other similar warming facilities, these IRHs haveminimum impacts on crop microclimate.Kimball et al.(2008) arranged six IRHs in anarray of 3-meter-dimater to uniformly warm wheat canopy.Due to lower turbulence andclosed stomata, IRH can cause greater increase in canopy temperature during nighttimethan during daytime.Rice production is suffering from asymmetric rise in day and nighttemperature which is evident from warming trend observed for Jiangsu province in thisstudy. In addition to changes in yield components, Post-anthesis B1 warming inducedchanges in the grain appearance quality, protein fractions (albumins-globulins, prolaminand glutelins) and amino acid contents of both hybrids.Warming during grain fillingenhanced formation of chalky grain and reduced the perfect grains.Grain internal structurewas also damages by the warming.Genotypic differences in their protein fractions andamino acid contents existed among the tested cultivars.Warming treatments inducedincreased in protein contents and amino acids significantly.Amino acids like cysteine,isoleucine, lysine and phenylalanine were not affected by warming treatments for bothcultivars, while other amino acids were significantly affected by temperature treatments.Different asymmetric temperature conditions exist between the quantities of each proteinfraction.From these results it was concluded that grain appearance quality and internalstructures were significantly deteriorated by post-anthesis asymmetric warming andgenotypic variations in protein fractions and amino acid contents were also influenced bytemperature during grain filling.
Experiments aimed to study responses of crops to rising temperature are mainlyconducted under controlled cover conditions like greenhouses, open-top chamber etc.These indoor facilities cannot mimic predicted climatic conditions and can significantlyalter crop microclimate.These potential artifacts can have undesirable impacts of plantgrowth and developmental processes.Use of infrared heaters (IRH) is one of the attractivealternatives which can provide reliable and reproducible canopy wanning for differentcrops in similar way they are heated by solar radiation.As compared to warming ingreenhouses, open-top champers and other similar warming facilities, these IRHs haveminimum impacts on crop microclimate.Kimball et al.(2008) arranged six IRHs in anarray of 3-meter-dimater to uniformly warm wheat canopy.Due to lower turbulence andclosed stomata, IRH can cause greater increase in canopy temperature during nighttimethan during daytime.Rice production is suffering from asymmetric rise in day and nighttemperature which is evident from warming trend observed for Jiangsu province in thisstudy. In addition to changes in yield components, Post-anthesis B1 warming inducedchanges in the grain appearance quality, protein fractions (albumins-globulins, prolaminand glutelins) and amino acid contents of both hybrids.Warming during grain fillingenhanced formation of chalky grain and reduced the perfect grains.Grain internal structurewas also damages by the warming.Genotypic differences in their protein fractions andamino acid contents existed among the tested cultivars.Warming treatments inducedincreased in protein contents and amino acids significantly.Amino acids like cysteine,isoleucine, lysine and phenylalanine were not affected by warming treatments for bothcultivars, while other amino acids were significantly affected by temperature treatments.Different asymmetric temperature conditions exist between the quantities of each proteinfraction.From these results it was concluded that grain appearance quality and internalstructures were significantly deteriorated by post-anthesis asymmetric warming andgenotypic variations in protein fractions and amino acid contents were also influenced bytemperature during grain filling.