水稻高光效育种的再探索图版Ⅰ

群体叶片截获光能能力的叶面积指数（ＬＡＩ）的发展和单个叶片光能转化效率的最大光合速率（Ｐｍ ａｘ）,是提高水稻光能利用效率的两大关键性的指标．利用适应低光强生态型的、ＬＡＩ发展快的广东优良品种“七桂早”,与适应高光强生态型的、Ｐｍ ａｘ 高的美国优良品种“Ｌｅｍ ｏｎｔ”为亲本,利用化学杂交剂组配成化杀杂种稻Ｌｅ／七,较好地解决了ＬＡＩ与Ｐｍａｘ的矛盾．Ｌｅ／七既保持了父本“七桂早”早期ＬＡＩ发展快的优点,又兼具有母本“Ｌｅｍ ｏｎｔ”Ｐｍａｘ较高、适应高光强的优点．杂种Ｌｅ／七在中午强光下光合作用“午睡”现象不明显,尤其是当广东出现造成水稻光氧化伤害的气象条件时,Ｌｅ／七的光氧化伤害很轻或无,比“七桂早”明显提高了对高光强的光能利用效率．对杂种Ｌｅ／七在人工气候箱不同控光控温条件下进行的生长分析,及在平原、丘陵及山区的试种,均表明其光合生产力和光合适应性比亲本有明显的提高和改进．研究表明∶利用美国适高光强的优良品种,通过组配成化杀杂种稻的途径,是改良广东水稻品种对高光强的光合适应性,提高光合生产力和经济效益的一条快速而有效的育种途径．     

黄土高原油松和刺槐叶片光合生理适应性比较

以黄土高原地区由南向北分布的杨凌、永寿、富县、安塞、米脂、神木等县为研究地点,研究不同地区油松和刺槐的光合特性与叶结构性状间的关系.结果表明,不同地区油松针叶和刺槐叶片的净光合速率（P_n）、光合氮利用效率（PNUE）、水分利用效率（WUE）、比叶质量（LMA）、氮含量（N_mass）和叶绿素相对含量（Chl）差异均达极显著水平（P＜0.001）,说明不同地区油松和刺槐的光合能力和叶结构性状参数差异很大.由南向北,油松的P_n、WUE和PNUE呈略微增加趋势,而刺槐则呈显著降低趋势,表明油松在干旱生境下仍能维持较高的光合能力,而刺槐光合能力明显受到抑制;油松和刺槐的LMA均呈略微上升趋势,而N_mass和Chl均呈略微下降趋势,且刺槐的变化幅度高于油松,说明油松从生理代谢和叶结构性状上对干旱环境的适应能力均强于刺槐.相关分析表明,不同地区油松和刺槐的LMA与N_mass整体上呈极显著负相关;P_n、PNUE与LMA、N_mass相关不显著,与Chl呈极显著正相关;WUE与LMA呈显著负相关（P＜0.05）,与N_mass呈显著正相关.     

Spatial patterns of photosynthetic characteristics and leaf physical traits of plants in the Loess Plateau of China

The spatial patterns of photosynthetic characteristics and leaf physical traits of 171 plants belonging to nine life-forms or functional groups (trees, shrubs, herbs, evergreen trees, deciduous trees, C₃ and C₄ herbaceous plants, leguminous and non-leguminous species) and their relationships with environmental factors in seven sites, Yangling, Yongshou, Tongchuan, Fuxian, Ansai, Mizhi and Shenmu, ranging from south to north in the Loess Plateau of China were studied. The results showed that the leaf light-saturated photosynthetic rate (P_max), photosynthetic nitrogen use efficiency (PNUE), chlorophyll content (Chl), and leaf mass per area (LMA) of all the plants in the Loess Plateau varied significantly among three life-form groups, i.e., trees, shrubs and herbs, and two groups, i.e., evergreen trees and deciduous trees, but leaf nitrogen content differed little among different life-form groups. For the 171 plants in the Loess Plateau, leaf P_max was positively correlated with PNUE. The leaf nitrogen content per unit area (N_area) was positively correlated but Chl was negatively correlated with the LMA. When controlling the LMA, the N_area was positively correlated with the Chl (partial r = 0.20, P < 0.05). With regard to relationships between photosynthetic characteristics and leaf physical traits, the P_max was positively correlated with N _area, while the PNUE was positively correlated with the Chl and negatively correlated with the N_area and LMA. For all the species in the Loess Plateau, the PNUE was negatively correlated with the latitude and annual solar radiation (ASR), but positively correlated with the mean annual rainfall (MAR) and mean annual temperature (MAT). With regard to the leaf physical traits, the leaf Chl was negatively correlated with the latitude and ASR, but positively correlated with the MAR and MAT. However, the N_area and LMA were positively correlated with the latitude and ASR, but negatively correlated with the MAR and MAT. In general, leaf N_area and LMA increased, while PNUE and Chl decreased with increases in the latitude and ASR and decreases in MAR and MAT. Electronic supplementary material The online version of this article () contains supplementary material, which is available to authorized users.     

杂交水稻及其亲本光合特性的研究 Ⅲ.功能叶片碳代谢中一些酶活性

对杂交水稻青优159（母本青A,父本R159）和广优四号（母本广A,父本青六矮）及其亲本功能叶片光合碳代谢中一些酶活性进行了研究。实验结果表明了两组杂交水稻的RuBPCase活性、RuBPCase/RuBPOase活性比值超过其各自的亲本;而杂交水稻青化159和广优四号的RuBPOase活性、乙醇酸氧化酶活性、光呼吸速率、光呼吸速率与光合速率的比值明显的低于其各自双亲．对RuBPCase活性和乙醇酸氧化酶活性与光合速率进行相关分析,结果表明RuBPCase活性与光合速率有正相关关系,相关系数为0．768;而乙醇酸氧化酶活性与光合速率负相关,相关系数为-0．834;两者均达到α＝0．05显著水平。     

Chemical agents that inhibit pollen development: effects of the phenyl-cinnoline carboxylates SC-1058 and SC-1271 on the ultrastructure of developing wheat anthers (Triticum aestivum L. var Yecora rojò)

Summary Phenylcinnoline carboxylate compounds SC-1058 and SC-1271 cause complete male sterility in wheat when applied at suitable dosages at the pre-meiotic stage of anther development. Anthers from treated and untreated plants were compared using light and electron microscopy from the pre-meiotic stage through the formation of nearly mature pollen. Overall anther development is gradually slowed in treated plants and pollen development is generally arrested in the late prevacuolate or early vacuolate microspore stage, although the first pollen mitosis does sometimes occur. The sporopollenin-containing exine walls are thinner, and show abnormally developed foot and tectum layers with sparse connecting baculi. Microspore cytoplasm degenerates and the cells eventually collapse. At the early, prevacuolate, free microspore stage treated tapetal cells hypertrophy, expanding into the locule. They contain abnormally large vacuoles that appear to form from the fusion of secretory vesicles, and some vacuoles contain electrondense deposits. The sporopollenin-containing orbicular wall and Ubisch bodies are retarded in their development and are structurally deformed. Acetolysis of whole anthers and of thick sections shows that the sporopollen-in-containing structures of treated materials are greatly reduced in thickness and are less rigid than in the control. We conclude that application of these compounds causes interference with the secretory function of tapetal cells which supplies sporopollenin cell-wall polymers to the exine of the microspores and to the tapetal orbicular wall and associated Ubisch bodies. Interference with the tapetal secretion of other nutrients required for microspore development is strongly suggested.     

Dynamics of leaf area and nitrogen in the canopy of an annual herb, <Emphasis Type="Italic">Xanthium canadense</Emphasis>

We studied leaf area and nitrogen dynamics in the canopy of stands of an annual herb Xanthium canadense, grown at a high (HN)- and a low-nitorgen (LN) availability. Standing leaf area increased continuously through the vegetative growth period in the LN stand, or leveled off in the later stage in the HN stand. When scaled against standing leaf area, both production and loss rates of leaf area increased but with different patterns: the production rate was retarded, while the loss rate was accelerated, implying an upper limit of standing leaf area of the canopy. The rate of leaf-area production was higher in the HN than in the LN stand, which was caused by the higher rate of leaf production per standing leaf area as well as the greater standing leaf area in the HN stand. Although the rate of leaf-area loss was higher in the HN than in the LN stand, it was not significantly different between the two stands when compared at a common standing leaf area, suggesting involvement of light climate in determination of the leaf-loss rate. On the other hand, the rate of leaf-area loss was positively correlated with nitrogen demand for leaf area development across the two stands, suggesting that leaf loss was caused by retranslocation of nitrogen for construction of new leaves. A simple simulation model of leaf and nitrogen dynamics in the canopy showed that, at steady state, where the rate of leaf-area loss becomes equal to the production rate, the standing leaf area was still greater in the HN than in the LN stand. Similarly, when the uptake and loss of nitrogen are equilibrated, the standing nitrogen was greater in the HN than in the LN stand. These results suggest that leaf-area production is strongly controlled by nitrogen availability, while both nitrogen and light climate determine leaf-loss rates in the canopy.     

Genetic variation in leaf pigment,optical and photosynthetic function among diverse phenotypes of <Emphasis Type="Italic">Metrosideros polymorpha</Emphasis> grown in a common garden

Coordinated variation has been reported for leaf structure, composition and function, across and within species, and theoretically should occur across populations of a species that span an extensive environmental range. We focused on Hawaiian keystone tree species Metrosideros polymorpha, specifically, 13-year old trees grown (2–4 m tall) in a common garden (approximately 1 ha field with 2–3 m between trees) from seeds collected from 14 populations along an altitude–soil age gradient. We determined the genetic component of relationships among specific leaf area (SLA), the concentrations of nitrogen (N) and pigments (chlorophylls, carotenoids, and anthocyanins), and photosynthetic light-use efficiency. These traits showed strong ecotypic variation; SLA declined 35% with increasing source elevation, and area-based concentrations of N, Chl a + b and Car increased by 50, 109 and 96%, respectively. Concentrations expressed on a mass basis were not well related to source elevation. Pigment ratios expressed covariation that suggested an increased capacity for light harvesting at higher source elevation; Chl/N and Car/Chl increased with source elevation, whereas Chl a/b declined; Chl a/b was higher for populations on younger soil, suggesting optimization for low N supply. Parallel trends were found for the photosynthetic reactions; light-saturated quantum yield of photosystem II (Φ _PSII) and electron transport rate (ETR) increased with source elevation. Correlations of the concentrations of photosynthetic pigments, pigment ratios, and photosynthetic function across the ecotypes indicated a stoichiometric coordination of the components of the light-harvesting antennae and reaction centers. The constellation of coordinated morphological, biochemical and physiological properties was expressed in the leaf reflectance and transmittance properties in the visible and near-infrared wavelength region (400–950 nm), providing an integrated metric of leaf status among and between plant phenotypes.     

Chemical agents that inhibit pollen development: tools for research

Summary Several unrelated compounds are known to selectively inhibit the development of the male gametophyte. When applied at suitable dosages to plants at the appropriate stages of anther development, these substances block the formation of fertile pollen. The affected stage of pollen development is characteristic of the specific chemical structure of the compound, ranging from effects on microspore meiosis to the formation of pollen defective in the ability to germinate or fertilize. The range of effects mediated by these substances, and by known male-sterile mutants, indicates that microspore development has several critical phases that are particularly sensitive to fatal inhibition. We propose that chemical inhibitors of pollen development deserve attention as tools for elucidating the regulation of pollen development.     

Variations and interrelationships of foliar hydraulic and photosynthetic traits for Larix gmelinii北大核心CSCD

Aims: Variations and potential trade-offs of leaf hydraulic and photosynthetic traits are essential for assessing and predicting the effect of climate change on tree survival, growth and distribution. Our aims were to examine variations and interrelationships of leaf hydraulic and photosynthetic traits in response to changes in site conditions for Dahurian larch (Larix gmelinii)-a dominant tree species in Chinese boreal forests. Methods: This study was conducted at the Maoershan Forest Ecosystem Research Station. A transect of 27 year-old Dahurian larch plantation was established that consisted of five plots extending from the valley to the ridge of a slope. The predawn leaf water potential (ψpre), area- and mass-based leaf hydraulic conductance (Karea and Kmass, respectively), resistance to embolism capacity (P50), leaf mass per area (LMA), net photosynthetic rate (A), and leaf nitrogen content (N) were measured in August 2016. Important findings: The ψpre, Karea, Kmass, P50, A, LMA, and N all varied significantly among the plots (p < 0.05), indicating significant intra-specific variations in these traits in response to the changes in site conditions. The P50 was significantly (p < 0.05) correlated with ψpre, Karea or Kmass, suggesting that a trade-off between hydraulic efficiency and safety exist within the species to some degree. There were significant (p < 0.05) pairwise correlations between A, LMA, and N. Nevertheless, there was no significant (p < 0.05) correlation between the measured photosynthetic traits and hydraulic traits. We concluded that the intra-specific variations and multiple interrelationships of the leaf hydraulic and photosynthetic traits for the larch reflect the plasticity of its leaf traits and strategies of its survival and growth as a result of its acclimation to diverse site conditions.     

中国北方杂草稻光合与水分生理特性

杂草稻是一类重要的稻属种质资源,具有耐寒、耐旱、耐瘠薄等优良特性.本文以88份中国北方杂草稻资源和4份栽培稻为材料,研究了中国北方杂草稻的光合速率、蒸腾速率、气孔导度等光合与水分生理特性及其相互关系.结果表明: 北方杂草稻资源的光合和水分生理特性存在较大差异,具有丰富的多样性.杂草稻的光合速率变化范围在12.47～28.67 μmol CO₂·m^-2·s^-1,瞬时水分利用效率的变化范围在1.39～3.40 mg·g^-1.光合参数中,胞间CO₂浓度的变异系数最小,气孔导度的变异系数最大.光合速率与蒸腾速率、气孔导度呈极显著的二次曲线关系,光合速率与胞间CO₂浓度呈显著的直线关系,瞬时水分利用效率与蒸腾速率、气孔导度呈极显著的二次曲线关系.可用杂草稻材料的优越性能对栽培稻进行品种改良.     

Pb、Ni胁迫对大羽藓抗氧化酶系统的影响

研究了Pb、Ni单一及复合胁迫下大羽藓细胞活性氧自由基的累积与清除、光合系统和膜系统的受损情况及其抗氧化酶系统的变化.结果表明：在较低胁迫浓度(Pb<0.1 mmol·L^-1,Ni<0.01 mmol·L^-1)下,大羽藓叶绿素含量具有应激效应,在较高胁迫浓度(Pb>0.1 mmol·L^-1,Ni>0.01 mmol·L^-1)下则具有抑制效应;随Pb-Ni复合胁迫浓度的增加,苔藓活性氧自由基和丙二醛的累积量逐渐增大;大羽藓超氧化物歧化酶和过氧化氢酶活性降低,过氧化物酶活性增加,过氧化物酶在清除Pb、Ni胁迫产生的活性氧自由基的过程中起着重要作用.大羽藓丙二醛含量和过氧化氢酶活性对Pb、Ni胁迫具有浓度依赖性,可以将其作为监测该类重金属污染的生物标志物.     

转玉米pepc基因水稻的某些光合特性

测定转玉米pepc基因水稻和未转化粳稻品种Kitaake在分蘖初期、分蘖盛期、拔节期、始穗期、齐穗期、成熟期和剑叶不同生长时期的光合特性动态变化的结果表明:转玉米pepc基因水稻的磷酸烯醇式丙酮酸羧化酶(PEPCase)活性和净光合速率(Pn)在不同时期各不相同,相对于Kitaake而言,均有不同程度的提高;剑叶完全展开时的PEPCase活性和Pn提高最明显.     

Vegetative structure,microclimate, and leaf growth of a páramo tussock grass species,in undisturbed,burned and grazed conditions

In neotropical alpine grasslands (páramo), the natural tussock grass vegetation is extensively grazed and occasionally burned. The low productivity of the tussock grass seems to be the reason for the disappearance of this growth form in the most frequently intervened areas. The structure, microclimate and leaf elongation rates of new emerging leaves were studied for the dominant tussock grass species Calamagrostis effusa, at an undisturbed, a moderately grazed (7 year after fire) and a heavily grazed (3.5 years after fire) site. In absence of grazing and burning, the tussocks had a high standing crop (1.07±0.09 kg DW · m^-2) and leaf area per projected tussock cover (LAI: 9.6±1.4). Two thirds of the total mass was dead and more than half of the leaves were in horizontal position. The tussock growth form protects the meristems from severe climatic conditions. At midday, the temperature was higher at meristem level than in the rest of the tussock. At this level, photosynthetic irradiance (PI) was almost extinct at 2.9±0.74% of PI above the vegetation. The red/far red ratio (R/FR) was strongly decreased. Initial leaf elongation of new born leaves was 2.3 mm · day^-1, and constant during the year; estimated net annual production was 198±73.8 g m^-2. At the moderately grazed and the heavily grazed study sites, the tussocks were smaller, greener and more erect than those at the undisturbed site. More PI reached the meristems and R/FR was higher at the base of grazed tussocks. Leaf elongation rates were lower. Most of the litter disappeared during the fires. The lower elongation rate of leaves in the grazed areas might be a response to defoliation, resulting in increased tillering and a lack growth associated with poor temperature insulation and more UV-B damage.     

Interspecific difference in the photosynthesis–nitrogen relationship: patterns,physiological causes,and ecological importance

The photosynthesis–nitrogen relationship is significantly different among species. Photosynthetic capacity per unit leaf nitrogen, termed as photosynthetic nitrogen-use efficiency (PNUE), has been considered an important leaf trait to characterise species in relation to their leaf economics, physiology, and strategy. In this review, I discuss (1) relations between PNUE and species ecology, (2) physiological causes and (3) ecological implications of the interspecific difference in PNUE. Species with a high PNUE tend to have high growth rates and occur in disturbed or high productivity habitats, while those with a low PNUE occur in stressful or low productivity habitats. PNUE is an important leaf trait that correlates with other leaf traits, such as leaf mass per area (LMA) and leaf life span, irrespective of life form, phylogeny, and biomes. Various factors are involved in the interspecific difference. In particular, nitrogen allocation within leaves and the mesophyll conductance for CO₂ diffusion are important. To produce tough leaves, plants need to allocate more biomass and nitrogen to make thick cell walls, leading to a reduction in the mesophyll conductance and in nitrogen allocation to the photosynthetic apparatus. Allocation of biomass and nitrogen to cell walls may cause the negative relationship between PNUE and LMA. Since plants cannot maximise both PNUE and leaf toughness, there is a trade-off between photosynthesis and persistence, which enables the existence of species with various leaf characteristics on the earth.     

Leaf phenology and seasonal variation of photosynthesis of invasive <Emphasis Type="Italic">Berberis thunbergii</Emphasis> (Japanese barberry) and two co-occurring native understory shrubs in a northeastern United States deciduous forest

Early leafing and extended leaf longevity can be important mechanisms for the invasion of the forest understory. We compared the leaf phenology and photosynthetic characteristics of Berberis thunbergii, an early leafing invasive shrub, and two co-occurring native species, evergreen Kalmia latifolia and late leafing Vaccinium corymbosum, throughout the 2004 growing season. Berberis thunbergii leafed out 1 month earlier than V. corymbosum and approximately 2 weeks prior to the overstory trees. The photosynthetic capacity [characterized by the maximum carboxylation rate of Rubisco (V _cmax) and the RuBP regeneration capacity mediated by the maximum electron transport rate (J _max)] of B. thunbergii was highest in the spring open canopy, and declined with canopy closure. The 2003 overwintering leaves of K. latifolia displayed high V _cmax and J _max in spring 2004. In new leaves of K. latifolia produced in 2004, the photosynthetic capacity gradually increased to a peak in mid-September, and reduced in late November. V. corymbosum, by contrast, maintained low V _cmax and J _max throughout the growing season. In B. thunbergii, light acclimation was mediated by adjustment in both leaf mass per unit area and leaf N on a mass basis, but this adjustment was weaker or absent in K. latifolia and V. corymbosum. These results indicated that B. thunbergii utilized high irradiance in the spring while K. latifolia took advantage of high irradiance in the fall and the following spring. By contrast, V. corymbosum generally did not experience a high irradiance environment and was adapted to the low irradiance understory. The apparent success of B. thunbergii therefore, appeared related to a high spring C subsidy and subsequent acclimation to varying irradiance through active N reallocation and leaf morphological modifications.     

高产早籼稻群体动态结构的差异

1998年早季在广州研究了不同类型高产早籼稻群体动态结构差异,结果认为:两系法杂交稻高产新组合培矮64s/E32、培矮64s/9311、粤杂122,其幼穗第2次枝梗原基分化期以前的植株干物重、叶面积指数（LAI）比常规稻高产品种粤香占和特三矮2号表现出明显的生长优势。培矮64s/E32在5个供试材料中在始穗期的LAI最高,达7.81,干物重日增量最大,达8.76kg/亩·d;粤香占的每亩有效穗数最高,达23.3万穗/亩,收获指数是所有参试材料中唯一达到 0.6以上者。     

中甸角蒿光合作用对生长光强的响应

在原生地和引种地对高山花卉中甸角蒿（1ncarvillea zhongdianensis）光合作用和叶片性状对生长光强的响应进行研究。结果表明：在香格里拉,光合速率（Pn）、类胡萝卜素（Car）、色素比（Chla/b）均随光强的降低而下降;而比叶面积（SLA）、叶绿素b（Chlb）、叶氮含量（LNCa）随光强的降低而上升。中甸角蒿主要是通过叶片形态、生化效率和叶片氮分配来响应生长光强的变化,对生长光强的适应表现出较大可塑性,使得其相对比较容易引种驯化。中甸角蒿在香格里拉对光照具有较广的适应幅,从香格里拉移栽到昆明后,虽然Pn下降约10%,但RGR增加约30%,表明其可以在昆明较好生长。     

阴雨寡照地区高产水稻的生物学特征研究

以水稻(Oryza sativa Linn.)的常规稻品种‘黄华占’、‘湘早籼45’和‘湘晚籼13’,一般杂交稻品种‘金优402’和‘Ⅱ优838’,超级杂交稻品种‘株两优819’、‘丰源优299’、‘陆两优966’和‘Y两优1号’为实验材料,在2008年和2009年不同产季,对种植于多阴雨的湖南桃源县的不同品种水稻的产量构成因子、群体性状和叶片净光合速率(Pn)差异进行了研究.结果显示:在产量构成因子方面,不同品种水稻的有效穗数、每穗粒数、结实率、千粒质量和产量均有一定差异,超级杂交稻品种的产量高于一般杂交稻及常规稻品种;其中,产量分别与有效穗数和结实率呈显著正相关(P＜0.05),与每穗粒数呈极显著正相关(P＜0.O1),与千粒质量无显著相关性.在群体性状方面,不同品种水稻的株高、最大茎蘖数、最大叶面积指数(LAI)、生物量及收获指数均有一定差异,但产量分别与株高、最大LAI和生物量呈极显著正相关,与收获指数呈显著正相关,与最大茎蘖数无显著相关性;其中,产量与最大LAI的相关系数最大(0.889).在拔节期和抽穗期,各品种水稻单叶的Pn日变化曲线呈“双峰型”,Pn第1个峰值差异均较小,“午休”阶段以及第2个峰值Pn差异增大,总体上看“午休”阶段常规稻品种的Pn降幅明显大于杂交稻;各品种的Pn日平均值也有明显差异,常规稻品种的Pn日平均值总体上低于杂交稻.研究结果表明:在阴雨寡照的生态条件下超级杂交稻品种的产量高于其他类型水稻品种,其高产机制与叶面积指数的增加有关.