大豆叶片光合速率与气孔导度、叶肉导度的关系

在田间条件下，研究１２个大豆品种两个生育时期的叶片光合速率（ＰＡ）、气孔导度（ｇｓ）、叶肉导度（ｇｍ）、气孔内ＣＯ２浓度（Ｃｉ）和蒸腾速率（ＴＲ）。结果表明，上述５个性状均有显著的品种间差异，并且鼓粒中后期明显大于开花前后。各性状的平均数在鼓粒中后期均极显著低于开花前后。ＰＡ与ｇｓ的关系，随生育期表现不同，在开花前后，可以配合成一条三次多项式曲线，并显示出一最大的ＰＡ值，而在鼓粒中后期则呈显著的线     

冬小麦基因型离体叶片失水与产量结构和植株性状的关系

根据４年的研究结果，分析了在冬小麦基因型产量和株高变异较大时，离体叶片失水速率（ＲＷＬ）与产量构成和植株性状的关系，研究表明，ＲＷＬ基因型间存在显著差异。在多数情况下ＲＷＬ与产量和千粒重呈负相关，与株高呈正相关。研究还发现基因型位次随失水时间的变化，有低失水，先快后慢，先慢后快和高失水４种类型。ＲＷＬ与产量负相关随失水时间延长而减弱。基因型差异以失水２－３ｈ最为明显，且更具有较大生理意义，因此提出     

冬小麦不同品种叶片光合速率与气孔导度等性状之间关系的研究

对４５个冬小麦品种不同生育期的叶片净光俣速率（Ｐｎ）、气孔导度（Ｇｓ）、胞间ＣＯ２浓度（Ｃｉ）、气孔阻力（ｒｓ）等４个性状的研究表明：４个性状在品种间均存在较大的差异；大部分品种的净光合速率（Ｐｎ）后期显著低于盛花期以前，几乎所有品种气孔阻力（Ｒｓ）盛花后期显著地低于盛花前期，气孔导度（Ｇｓ）和胞间ＣＯ２浓度则恰好相反；净光合速率（ｐｎ）在盛花前期主要受气孔因素限制，盛花后期主要受非气孔因素限制。     

不同供水条件下小麦不同绿色器官的气孔特性研究

为了考察小麦叶片与非叶器官气孔结构特性的差异及其对供水条件的反应，本研究设置不同灌水处理，利用电镜观察小麦灌浆期不同绿色器官的气孔分布和结构特征，并分析其与气孔特性指标间的关系。结果表明，在不同灌水处理下看到各非叶器官（穗、旗叶鞘和穗下节间）均分布着气孔，但其数目少于旗叶叶片。护颖仅在远轴面存在气孔；外稃在多水条件下（4水处理）近轴面出现较多气孔，而远轴面看不到气孔，但在水分胁迫（无水处理）条件下，气孔却出现在远轴面而不在近轴面；在不同水分处理下均观察到芒上明显的气孔分布。从气孔大小看，穗各部分（护颖、外稃、内稃和芒）略小于其他器官。随着灌水次数的减少，各器官气孔密度呈增大趋势，气孔器及气孔孔径表现出长度增加、宽度减小的特征。限水灌溉下非叶器官（穗、旗叶鞘和穗下节间）在籽粒灌浆期气孔导度、蒸腾速率和光合速率的稳定性高于叶片。相关分析表明，不同器官的气孔导度与蒸腾速率均呈显著正相关，非叶器官气孔导度与光合速率的相关程度明显低于叶片。说明在干旱少水条件下，叶与非叶器官蒸腾作用均会减弱，叶片光合速率亦相应降低，而非叶器官光合速率可能保持相对稳定，可相对提高其水分利用效率。     

水稻开花后叶片含氮量与光合作用的动态变化及其关系

对９个日本栽培水稻品种盆栽植株开花后叶片含氮量与光合作用的动态变化及其关系的研究表明，水稻开花后叶片全氮含量（ＴＮＣ）、净光合速率（Ｐｎ）和氮的光合效率（Ｐｎ／Ｎ，即Ｐｎ与ＴＮＣ的比值）呈持续性下降。增施氮肥的植株叶片ＴＮＣ增加，并延缓Ｐｎ和Ｐｎ／Ｎ的下降。增施氮肥对早熟品种叶片ＴＮＣ和Ｐｎ的促进作用大于中熟品种。水稻品种间叶片ＴＮＣ的变化较小，Ｐｎ和Ｐｎ／Ｎ的变化较大。随着测定时期的推移，品种间     

芹菜耐寒性的初步鉴定

实验选择6个芹菜品系,在18℃/14℃（d/n）（CK）和14℃/10℃（d/n）、10℃/10℃（d/n）低温胁迫处理下,通过测定生长量、膜稳定性、游离脯氨酸、可溶性糖、可溶性蛋白质等指标综合评价筛选确定了6个（10、14、16、20、22、24）品系的耐低温胁迫能力,结果表明：低温胁迫研究中采用10℃/10℃（d/n）处理芹菜幼苗比较合理。此处理温度对芹菜造成的影响在品系间存在显著差异;筛选出具备良好的耐低温胁迫能力的芹菜育种材料24号品系。在上述各单项指标测定结果间比较可以看出,部分品系耐低温能力在排序中位次有一定差异,但其中有一些品系的耐低温能力总体上还是比较稳定的（如24、14等）,可以说明耐低温能力的趋势。     

豇豆胰蛋白酶抑制剂(CpTI)基因在转基因水稻中的表达特性研究

以豇豆胰蛋白酶抑制剂(CpTI)转基因水稻自交品系和其衍生的花培品系为实验材料，通过PCR扩增和CpTI表达蛋白活性的测定，研究了CpTI基因的遗传稳定性和表达特性。结果表明CpTI基因在转基因自交后代可以稳定遗传，而在部分花培品系中发生丢失。同时CpTI基因的表达表现出一定的时空特性，同一转基因品系中叶片CpTI蛋白的表达活性通常高于茎杆，而不同发育时期的CpTI蛋白的表达活性以分蘖期最高。除花培品系DH401外，转基因品系叶片和茎杆的蛋白酶抑制剂的活性随着水稻的生长发育呈下降的趋势。     

玉米（Zea maysL.）杂交种（中单14）及其亲本部分光合特性的研究

叶片叶绿素荧光动力学参数证明，与两亲相比，玉米杂交处叶绿体类囊体膜的ＰＳⅡ还原侧有较大的ＰＱ电荷库（ＣＡ／Ｆ０），可以加快两个光系统间的非循环电子传递速率，有利于光合膜的能态化（△Ｆ／Ｔ和△Ｆ／Ｔ），调节有效的光合磷酸化。同时，杂交种具有较魇光合单位（Ｔ１／２）。这些都有利于光能吸收和提高光能转化效率及光合作用速率。整体叶片光合强度的测定结果支持了上述分析。     

水分胁迫对水稻叶片气孔频率,气孔导度及脱落酸含量的影响

试验结果表明，在水分胁迫条件下，水稻新生叶片的气孔频率增大，气孔频率最大值的出现推迟；土壤水分充足（对照）或水分胁迫３天的处理在叶片上有两个气孔频率的高峰，水分胁迫５天的处理仅有一个；随着水分胁迫的加重，保卫细胞长度变短，但叶片顶部和基部保卫细胞长度变化较小，中部的变化较大；水分胁迫后，气孔导度变小，复水后迅速上升，上升的速度因品种不同而有较大差异；在较高叶片水势下，品种盐粳２号叶片的脱落酸（ＡＢ     

小麦叶片CO2／H2O交换参数在不同供水条件下的反应

在大田不同供水条件下,于小麦孕穗期和灌浆期对小麦叶片气体交换参数的日变化进行了连续测定。结果表明,小麦叶片光合速率（Ｐｎ）,气孔导度（Ｇａ）蒸腾速率（Ｔｒ）以及叶肉细胞间隙ＣＯ２浓度（Ｃｉ）均有较明显的日变化,不同供水条件下,Ｐｎ的日变化趋势不同,充分供不时为典型的双峰曲线,中午有明显的“午休”现象,当非充分供水时,Ｐｎ午休现象明显,且持续时间长,第二高峰表现不明显。供水条件较好时,小麦叶片Ｇｓ,     

不同冬小麦品种的离体叶片失水速率差异及对供水的反应

较低的离体叶片失水速率(RWL)与抗旱性有关已经得到很多研究者的认同.选取8个冬小麦品种为试材,设置干旱(0水)、节水(2水)和足水(4水)的水分条件,研究不同冬小麦品种对供水条件的反应和生育时期的RWL变化特征.结果表明:不同品种间的RWL差异不显著.RWL随着灌水次数的增加而增高.0水处理的衡7228 RWL最低,冀5579和石麦16也较低.2水处理的石麦16最低,石麦14和冀5579也较低.4水处理下,石新618 的RWL最低,石麦14和衡7228较低,综合3种灌水结果,石麦16、冀5579和石麦14抗旱节水性较好.RWL随着生育进程而变化,拔节期较低,逐渐增加,至抽穗期达到峰值,此后明显下降,直至成熟.前期控水对降低小麦离体叶片失水速率,提高抗旱节水性有利.     

Efficient selection of potato heterokaryons by flow cytometric sorting and the regeneration of hybrid plants

Drought is one of the important factors limiting crop production in arid and semi-arid regions. Four drought resistance criteria, consisting of canopy temperature, stomatal resistance, transpiring area and rate of water loss by excised-leaves were examined in two experiments conducted in optimum and stress moisture conditions in 1995. A randomized complete block design with four replications and six genotypes was used for each experiment. Under optimum moisture conditions, there was a significant difference in canopy temperature at midday between drought resistant and drought sensitive genotypes. A significant linear relationship was also obtained between this criterion and yield reduction ratio as determined by Y_r = 1-(Y_s/Y_p) (Y_s and Y_p = yield under stress and non-stress conditions, respectively), at the ear emergence stage. The only significant difference between cultivars in respect to stomatal resistance in stress conditions was that of adaxial leaf surface in ear emergence stage. No significant linear relationship was obtained between transpiring area and yield reduction ratio. Cultivars differed in respect to rate of water loss (RWL) and initial water content (IWC) in ear emergence and grain filling in stress environment only. Ultimately, three criteria namely canopy temperature, stomatal resistance and RWL, in explicated conditions were recognized as benificial drought resistance indicators. This revised version was published online in July 2006 with corrections to the Cover Date.     

不同栽培模式下水稻产量差异的研究

为查明栽培模式对水稻产量的影响,采用田间试验方法,设置3个处理：插秧、撒播和条播,对其产量及其构成进行了测定,就不同栽培模式下水稻产量差异的原因进行了研究。结果表明,插秧水稻的产量(10390 kg/hm2)要高于撒播(7790.7 kg/hm2)和条播(9105.2 kg/hm2),3种栽培模式下水稻的收获指数几乎没有不同(撒播、条播和插秧分别为56.5、54.7、53.9),而插秧水稻的地上部干物质量明显高于撒播和条播,更高的地上部干物质量使插秧水稻形成了更大的单位面积穗数和穗粒数,特别是后者较撒播和条播分别高39.0%和26.9%,其与水稻产量呈显著的正相关关系(相关系数0.795)。3种栽培模式相比,条播水稻的效益成本比最高,达到了2.52。总之,与直播(撒播、条播)相比,插秧水稻获得高产的根本原因是其具有更大的穗粒数,但考虑到成本投入,在实际生产中,条播水稻的收益更高。     

大豆生物量积累、收获指数及产量间的相关与QTL分析

利用亲本间生物量、收获指数和产量有较大差异的南农1138-2和科丰1号杂交衍生的大豆重组自交家系(NJRIKY), 研究始花期(R1)、始荚期(R3)、始粒期(R5)、收获期生物量以及表观收获指数和产量间的相关, 并进行QTL定位, 分析相关的遗传基础。结果表明, (1) 生物量与产量显著相关, 相关程度随生长进程逐渐增加, 收获期生物量与产量相关最高, R²=0.76。R1、R3、R5期生物量与产量的相关呈负指数曲线相关, 生物量分别达到1 000、2 300和5 500 kg hm^-2时, 产量不再随生物量的增加而增加。收获期生物量与产量呈直线正相关, 在试验范围内未发现高产的收获期生物量上限。表观收获指数与产量呈指数曲线相关, 小于0.42时与产量具正变关系, 大于0.42时与产量具负变关系。收获期生物量与表观收获指数呈指数曲线相关, 表观收获指数增加生物量降低。(2) 检测到产量、表观收获指数、收获期生物量有关的QTL分别为9、10和10个, 其中两年稳定的QTL分别有2、3、3个。检测到R1、R3和R5期生物量有关的QTL分别有6、9和6个, 其中3个时期在两年均能稳定表达的有2个。(3)在9个产量QTL中的6个区间, 还同时检测到生物量和表观收获指数有关的QTL, 该3性状有部分QTL共享同一连锁区间, 表明有其共同的遗传基础, 同时也解释了性状间相关的遗传原因。     

陆地棉产量育种动态模型探讨

应用典型相关分析方法,对１２０个陆地棉品系产量构成的三个因素进行分段研究表明,（１）构成皮棉产量的三因素间存在动态平衡,不同组合模式,其产量表现不同。（２）单株铃数、衣分、铃重都存在最佳选择范围,在此范围内容易形成高产皮棉的优化组合。（３）三因素中某一因素的过高选择,会降低另外两个因素的选择动态,不易形成最佳产量组合。     

QTLs for water absorption and flour yield identified in the doubled haploid wheat population Lang/QT8766

Two key quality traits in milling wheat are flour yield (FY) and water absorption (WA). Ideally, breeders would prefer to use markers to select promising lines rather than time consuming rheology tests. In this study, we measured FY and WA on a wheat mapping population (Lang/QT8766) of 162 individuals grown in two replicated field experiments at three locations over 2 years. We also carried out near infrared reflectance spectroscopy (NIRS) predictions on the grain for these traits to see if NIRS phenotypic data could provide useful mapping results when compared to the reference phenotypic data. Several common QTLs were identified for FY and WA by both sets of data. The QTL on chromosome 4D was a consistently recurring QTL region for both traits. The QTL on chromosome 2A was positively linked to protein content which was supported by genetic correlation data. The results also indicated it was possible to obtain useful phenotypic data for mapping FY and WA using NIRS data. This would save time and costs as NIRS is quicker and cheaper than current rheology methods.     

Higher forage yields under temperate drought explained by lower transpiration rates under increasing evaporative demand

In temperate regions, perennial forage-based cropping systems are expected to face an increasing frequency of summer droughts over the next decades prompting the need for more resilient cultivars. However, most efforts mainly focus on Mediterranean-type environments where the plant survival is often engaged. Under temperate environments, vapor pressure deficit (VPD) is a key component of drought, because its variation alters the crop transpiration rate (TR) and therefore its ability to fix carbon even in well-watered conditions. Despite this knowledge, there is no available data about the diversity of whole-plant TR responses to VPD and soil moisture among key forage crops such as alfalfa, red clover, cock’s foot and perennial ryegrass. Further, field-based evidence is lacking regarding the links between TR responses to VPD and yield under drought. Here, we combined experimental approaches characterizing gas exchange responses to VPD and soil moisture at scales that ranged from the growth chamber to the field, where yields were characterized both quantitatively and qualitatively over the course of 2 years on 8 genotypes from the 4 above species. A significant variability in TR responses to increasing VPD and soil water deficit was found among locally-adapted cultivars. More importantly, TR responses to VPD – but not to decreasing soil moisture – were found to be consistently correlated to relative yield performances under drought, in a way indicating that conservative water use under high evaporative demand promoted higher yield outputs. In contrast, yields under drought were unrelated to canopy temperature and leaf gas exchange measured in the field. Further, no link was found between TR responses to VPD and qualitative yield traits such as digestibility indicating that the hypothesized water saving strategy does not improve yield at the expense of forage quality. This study opens the way for future forage breeding and management strategies taking advantage of the diversity of TR responses to drought to implement climate-change resilient forage-based systems.     

Transpiration Sensitivity to Evaporative Demand Across 120 Years of Breeding of Australian Wheat Cultivars

Historically, wheat yields in drought‐prone Australian environments have been consistently increasing for over a century. There is currently an agreement that approximately half of that increase is attributable to breeding programmes, but their physiological basis remains poorly documented. In this investigation, we hypothesized that limited whole‐plant transpiration rate (TR) under high atmospheric vapour pressure deficit (VPD) could result in advantageous water conservation and crop yield increase under south Australian conditions. Therefore, TR response to VPD was measured in the 0.9–3.2 kPa range for a group of 23 wheat cultivars that were released from 1890 to 2008. Consistent with a water‐conservation hypothesis, all genotypes displayed a VPD break point (BP) in TR with increasing VPD such that TR was limited at VPD above a BP of about 2 kPa. The BP and slope of TR with increasing VPD above the break point were correlated with the year of release, although the changes were in different directions. Such changes in these transpiration parameters were independent of plant leaf area and only marginally correlated with Zadok's stages. These results indicated that selection over 120 years by breeders for yield increase unconsciously resulted in genotype selection for the expression of the limited‐TR trait.     

利用混合线性模型分析绿豆主要农艺性状的遗传及相关性

以19个绿豆品种(系)为亲本, 采用非完全双列杂交试验设计及混合线性模型,研究绿豆主要农艺性状的遗传规律及其性状间的相互关系。结果表明, 绿豆全生育日数、株高、主茎节数和百粒重均以加性效应为主, 狭义遗传率较高且达极显著水平;单株荚数、单株产量和总产量的加性效应和显性效应均显著或极显著, 狭义遗传率相对较低;单荚粒数主要受显性效应影响, 广义遗传率较高;播种至开花天数与株高间存在显著或极显著遗传和表型正相关;单株荚数、单荚粒数与百粒重显著或极显著负相关;单株荚数与单株产量、总产量显著或极显著正相关;百粒重与单株产量、总产量相关性不大;针对全生育日数、株高、主茎节数和百粒重的选择可在早期世代进行, 而对产量的选择可以根据单株荚数和单株产量在晚期世代进行。