Ear photosynthesis, carbon isotope discrimination and the contribution of respiratory CO2 to differences in grain mass in durum wheat

开花 光合作用 苞片 农学 生物 标志(线性代数) 蒸腾作用 碳同位素 气孔导度 园艺 植物 数学 总有机碳 栽培 花序 纯数学 域代数上的 生态学
作者
J. L. Araus,Harold R. Brown,Anna Febrero,J. Bort,María Dolores Serret
出处
期刊:Plant Cell and Environment [Wiley]
卷期号:16 (4): 383-392 被引量:199
标识
DOI:10.1111/j.1365-3040.1993.tb00884.x
摘要

ABSTRACT The role of ear photosynthesis in grain filling was studied in a number of durum wheat ( Triticum turgidum var durum L.) landraces and varieties from the Middle East, North Africa, and from the collections of ‘Institut National de la Recherche Agronomique’ (INRA, France) and ‘Centro International de Mejora de Maiz y Trigo’ (CIMMYT, Mexico). Plants were grown in the field in a Mediterranean climate. Flag leaves (blade plus sheath) and ears were kept in the dark from 1 week after anthesis to maturity which reduced grain weight by 22.4% and 59.0%, respectively. In a further experiment, the carbon isotope discrimination ratio (Δ) of ear bracts, awns and flag leaves was measured on samples taken at anthesis and on mature kernels. The mean value of Δ for the water soluble fraction of bracts (17.0‰) and awns (17.7‰) were lower than those of leaves (19.5‰) and fairly similar to those of kernels (17.4‰) averaged across all genotypes. Data indicate that most of the photosynthates in the grain come from ear parts and not from flag leaves. In addition, a higher water use efficiency (WUE) of ear parts than of the flag leaf is suggested by their lower Δ values. Gas exchange in ears and flag leaves was measured during grain filling. Averaged over all genotypes, CO 2 diffusive conductance was about five times higher in the flag leaf than in the spike (with distal portions of awns outside the photosynthetic chamber) 2 weeks after anthesis. In absolute terms, the dark respiration rate (R d ) was greater than the net photosynthesis rate (P n ) by a factor of 1.74 in the spike, whereas R d was much smaller, only 22.1, 65.7 and 24.8% of P n in blade, sheath and awns, respectively. Data indicate that photosynthesis, and hence the water use efficiency (photosynthesis/transpiration), is greatly underestimated in ears because of the high rates of respiration which diminish the measured rates of net CO 2 exchange. Results of 13 C discrimination and gas exchange show that genotypes from North Africa have higher WUE than those from the Middle East. The high R d values of ears as well as their low diffusive conductance suggest that CO 2 from respiration may be used as source of carbon for ear photosynthesis. In the same way, the anatomy of glumes, for example, supports the role of bracts using internal CO 2 as source of photosynthesis. In the first experiment, the Δ in mature grains from culms with darkened ears compared with control culms provided further evidence in support of this hypothesis. Thus, the Δ from kernels of control plants was 0.40 higher than that from ear‐darkened plants, probably because of some degree of refixation (recycling) of respired CO 2 in the grains.
最长约 10秒,即可获得该文献文件

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
大幅提高文件上传限制,最高150M (2024-4-1)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
言不得语发布了新的文献求助10
刚刚
陶醉的妖丽完成签到 ,获得积分10
2秒前
当当发布了新的文献求助10
3秒前
RUI发布了新的文献求助10
4秒前
快乐映秋完成签到,获得积分10
5秒前
weeqe完成签到,获得积分10
6秒前
511完成签到 ,获得积分10
7秒前
昵称完成签到,获得积分10
9秒前
小捷子完成签到,获得积分10
11秒前
liaomr完成签到 ,获得积分10
12秒前
科研通AI2S应助萨摩耶耶采纳,获得10
13秒前
txmjsn完成签到,获得积分10
15秒前
Ade完成签到,获得积分10
15秒前
果冻完成签到,获得积分10
16秒前
当当完成签到,获得积分20
16秒前
Hello应助koi采纳,获得10
17秒前
852应助科研达人采纳,获得10
17秒前
17秒前
NJY完成签到,获得积分10
18秒前
18秒前
若宴不在家关注了科研通微信公众号
20秒前
22秒前
终于花开日完成签到 ,获得积分10
22秒前
苏晓醒完成签到,获得积分10
22秒前
23秒前
Gilbert完成签到,获得积分20
23秒前
24秒前
24秒前
139完成签到 ,获得积分0
24秒前
gz000111完成签到,获得积分10
25秒前
天天快乐应助huofuman采纳,获得10
25秒前
俭朴的皮卡丘完成签到 ,获得积分10
26秒前
认真丹亦完成签到 ,获得积分10
27秒前
nicole完成签到,获得积分10
28秒前
28秒前
惜墨发布了新的文献求助30
28秒前
zz发布了新的文献求助10
28秒前
laihama完成签到,获得积分10
28秒前
秋日繁星发布了新的文献求助30
29秒前
隐形曼青应助Linyi采纳,获得10
29秒前
高分求助中
Sustainability in Tides Chemistry 2800
The Young builders of New china : the visit of the delegation of the WFDY to the Chinese People's Republic 1000
Rechtsphilosophie 1000
Bayesian Models of Cognition:Reverse Engineering the Mind 888
Handbook of Qualitative Cross-Cultural Research Methods 600
Very-high-order BVD Schemes Using β-variable THINC Method 568
Chen Hansheng: China’s Last Romantic Revolutionary 500
热门求助领域 (近24小时)
化学 医学 生物 材料科学 工程类 有机化学 生物化学 物理 内科学 纳米技术 计算机科学 化学工程 复合材料 基因 遗传学 催化作用 物理化学 免疫学 量子力学 细胞生物学
热门帖子
关注 科研通微信公众号,转发送积分 3137206
求助须知:如何正确求助?哪些是违规求助? 2788244
关于积分的说明 7785188
捐赠科研通 2444219
什么是DOI,文献DOI怎么找? 1299854
科研通“疑难数据库(出版商)”最低求助积分说明 625606
版权声明 601011