Mechanical transplanting has been applied to rice cultivation to save labor costs and ease labor shortages in Asian countries, especially in China. However, little information is available related to the characteristi...Mechanical transplanting has been applied to rice cultivation to save labor costs and ease labor shortages in Asian countries, especially in China. However, little information is available related to the characteristics of agronomic performance when comparing inter-sub-specific hybrid rice(IHR) and inbred japonica rice(IJR) under mechanical transplanting method. In 2013 and 2014, field experiments were conducted using IHR(Yongyou 2640) and IJR(Wuyunjing 24) under two cultivation patterns, that is, pot seedlings mechanically transplanted(PS) and carpet seedlings mechanically transplanted(CS). Grain yield, yield components, leaf area index(LAI), leaf area duration(LAD), aboveground biomass, crop growth rate(CGR), nitrogen(N) uptake, and N accumulation were investigated. When compared with CS, PS displayed significantly increased grain yield for both varieties because the larger sink size allowed higher N accumulation from panicle initiation to maturity. Moreover, total aboveground biomass under PS increased significantly compared with that under CS; that is, higher photosynthetic productivity resulted from a greater LAI and higher LAD during the grain filling stage. Higher N absorption capacity in the middle and late growth periods resulted in significantly enhanced total N uptake under PS. When compared with IJR for both treatments, IHR generated 75.2% more grain yield. However, the characteristics creating high yield of IHR were different from those of IJR. Greater aboveground biomass production as well as higher N uptake and accumulation created higher grain yield in IHR than in IJR. These results suggest higher yield could be achieved using PS with IHR, attributing to exploit both yield superiority and productive potential.展开更多
以母本中国南瓜(Cucurbita moschata Duch.)MO和父本印度南瓜(Cucurbita maxima Duch.)MA为对照,通过测定热胁迫前后植株叶片的相对电导率(E)、计算伤害率(RI)以及正向超亲优势PHA值和负向超亲优势NHA值,对36个中(MO)×印(MA)南瓜...以母本中国南瓜(Cucurbita moschata Duch.)MO和父本印度南瓜(Cucurbita maxima Duch.)MA为对照,通过测定热胁迫前后植株叶片的相对电导率(E)、计算伤害率(RI)以及正向超亲优势PHA值和负向超亲优势NHA值,对36个中(MO)×印(MA)南瓜远缘杂交新种质的F5和F6自交系进行耐热性评价。结果显示,RI对材料耐热性差异区分度高,与植株耐热表型结果吻合,与植物耐热性负相关,可直观评价中印南瓜远缘杂种后代耐热性。供试南瓜材料在热处理之后,相对电导率(E)均升高,表明热处理破坏了叶片细胞膜;不同材料之间相对电导率增加幅度不同,表明材料间细胞膜热稳定性存在差异。中国南瓜MO比印度南瓜MA耐热性强,其RI值分别为0.24±0.10和0.65±0.29。以MO和MA的RI值为阈值,共筛选到16个耐热株系(PHA值为-8.3%^-87.5%,平均值为-54.1%,PHA绝对值越大,正向超亲优势越明显),14个不耐热株系(NHA值为3%~40%,平均值为24.3%),及6个耐热性介于亲本之间的株系。供试材料整体上的耐热性呈两级分化,耐热性增强效果明显。F4的耐热性存在分离,18SH和18SE的后代耐热性增强,18SF耐热性减弱。以RI值0.15为阈值,筛选到13个表现出超亲优势的耐热株系,包括源于18SH的10个F5株系,2个源于18SE的F5株系和1个源于18FB的F6株系。筛选的耐热优系,为培育适宜越夏栽培的耐热印度南瓜新品种提供有价值的亲本。展开更多
基金the National Key Research Program of China(2016YFD0300503)the Special Fund for Agro-scientific Research in the Public Interest,China(201303102)+2 种基金the Key Research Program of Jiangsu Province,China(BE2016344)the Major Independent Innovation Project in Jiangsu Province,China(CX(15)1002)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Mechanical transplanting has been applied to rice cultivation to save labor costs and ease labor shortages in Asian countries, especially in China. However, little information is available related to the characteristics of agronomic performance when comparing inter-sub-specific hybrid rice(IHR) and inbred japonica rice(IJR) under mechanical transplanting method. In 2013 and 2014, field experiments were conducted using IHR(Yongyou 2640) and IJR(Wuyunjing 24) under two cultivation patterns, that is, pot seedlings mechanically transplanted(PS) and carpet seedlings mechanically transplanted(CS). Grain yield, yield components, leaf area index(LAI), leaf area duration(LAD), aboveground biomass, crop growth rate(CGR), nitrogen(N) uptake, and N accumulation were investigated. When compared with CS, PS displayed significantly increased grain yield for both varieties because the larger sink size allowed higher N accumulation from panicle initiation to maturity. Moreover, total aboveground biomass under PS increased significantly compared with that under CS; that is, higher photosynthetic productivity resulted from a greater LAI and higher LAD during the grain filling stage. Higher N absorption capacity in the middle and late growth periods resulted in significantly enhanced total N uptake under PS. When compared with IJR for both treatments, IHR generated 75.2% more grain yield. However, the characteristics creating high yield of IHR were different from those of IJR. Greater aboveground biomass production as well as higher N uptake and accumulation created higher grain yield in IHR than in IJR. These results suggest higher yield could be achieved using PS with IHR, attributing to exploit both yield superiority and productive potential.
文摘以母本中国南瓜(Cucurbita moschata Duch.)MO和父本印度南瓜(Cucurbita maxima Duch.)MA为对照,通过测定热胁迫前后植株叶片的相对电导率(E)、计算伤害率(RI)以及正向超亲优势PHA值和负向超亲优势NHA值,对36个中(MO)×印(MA)南瓜远缘杂交新种质的F5和F6自交系进行耐热性评价。结果显示,RI对材料耐热性差异区分度高,与植株耐热表型结果吻合,与植物耐热性负相关,可直观评价中印南瓜远缘杂种后代耐热性。供试南瓜材料在热处理之后,相对电导率(E)均升高,表明热处理破坏了叶片细胞膜;不同材料之间相对电导率增加幅度不同,表明材料间细胞膜热稳定性存在差异。中国南瓜MO比印度南瓜MA耐热性强,其RI值分别为0.24±0.10和0.65±0.29。以MO和MA的RI值为阈值,共筛选到16个耐热株系(PHA值为-8.3%^-87.5%,平均值为-54.1%,PHA绝对值越大,正向超亲优势越明显),14个不耐热株系(NHA值为3%~40%,平均值为24.3%),及6个耐热性介于亲本之间的株系。供试材料整体上的耐热性呈两级分化,耐热性增强效果明显。F4的耐热性存在分离,18SH和18SE的后代耐热性增强,18SF耐热性减弱。以RI值0.15为阈值,筛选到13个表现出超亲优势的耐热株系,包括源于18SH的10个F5株系,2个源于18SE的F5株系和1个源于18FB的F6株系。筛选的耐热优系,为培育适宜越夏栽培的耐热印度南瓜新品种提供有价值的亲本。
