Evaluation of Genetic Traits for Improving Productivity and Adaptation of Groundnut to Climate Change in India

Anticipated climate change will alter the temperature and rainfall characteristics of crop growing seasons. This will require genetic improvement of crops for adapting to future climates for higher yields. The CROPGRO model for groundnut was used to evaluate genetic traits of Virginia and Spanish types of groundnut for various climate scenarios of India. The analysis revealed that productivity of groundnut can be increased in current and future climates by adjusting the duration of various life‐cycle phases, especially the seed‐filling to physiological maturity (SD‐PM). Increased maximum leaf photosynthesis rate (AMAX), increased partitioning to reproductive organs (XFRT) and increased individual seed‐fill duration (SFDUR) all contributed to the increase in pod yield in all climates. More determinate pod set (shorter PODUR) was beneficial only in the water deficit environments. The positive effect of increasing specific leaf area (SLA) and leaf size (SIZLF) on pod yield was greater in environments more favourable for plant growth. Increasing reproductive tolerance to high temperature by 2 °C increased pod yield of groundnut in warmer environments, especially where the crop often suffers from drought. Increased adaptive partitioning to roots (ATOP) increased drought resistance of groundnut on high water‐holding capacity soils. Combination of traits had additive effects and pod yield increased substantially. These results indicate that the CROPGRO model can be used to assess the potential of individual or combination of plant traits for guiding breeding of improved groundnut varieties for current and future climates.     

An Analysis of Grain Development in Oryza sativa L. Cultivars

A field study was conducted to determine if differences in grain filling rate and duration existed in two early cultivars of rice. There is no cultivar difference in duration of grain filling and grain matured in about 30 days from anthesis in both the cultivars. The effective grain filling period in rice is only 10 days between 3rd and 13th day from anthesis. There is significant difference in grain filling rate and is positively related to grain weight. Grain filling rate is more important than duration of filling for achieving higher grain size and thus yield in rice.     

Carbohydrate Metabolism in the Siliqua Relating to Oil-filling in Mustard Seeds

Developing siliquas on the mustard inflorescence were sampled at basal, middle and apical positions and the changes in free sugars and starch in pod wall and seed vis-á-vis oil-filling in the seeds were studied. The dry matter and oil content per seed and pod wall was highest at initial stages in apical followed by mid-development stages in middle and late development stages in basal positions. The oil percentage m the pod wall decreased with the period of siliqua development. The phase of rapid oil filling in the seeds varied from 20 to 40 DAF (days after flowering) in basal to 10 to 30 DAF in middle and 10 to 20 DAF in apical positions. The content of starch and total soluble sugars (% dry weight basis) decreased in the seeds as well as pod walls but showed accumulation on per seed basis with a maximum at 20, 30 and 40 DAF while on pod wall basis, the maxima of total soluble sugars was at 20, 20 and 40 DAF in apical, middle and basal position respectively. In the pool of total soluble sugars, the proportion of non-reducing sugars was predominant. The activity of invertase (EC 3.2.1.26) declined while those of a-amylase (EC 3.2.1.1) and β-amylase (EC 3.2.1.2) showed maximum values in the seeds as well as pod wall during the phase of rapid oil-filling in the seeds. The results suggested that ontogeny and duration of seed development vis-á-vis the environmental conditions played an important role in lipid biosynthesis in mustard seeds.     

大豆炸荚表型精准检测方法的研究

大豆炸荚表型易受环境影响,炸荚相关研究的关键在于如何获得精准的表型。以遗传背景较近且炸荚表型差异较大的2份栽培大豆为材料,利用烘箱对2个品种完熟期不同部位的豆荚进行炸荚率检测,烘干温度和持续时间各设置5个处理。结果表明,不同处理下大豆各部位的炸荚率无显著差异,炸荚率与烘干温度及持续时间呈显著正相关;不同品种大豆炸荚率在60℃、11h后的处理均存在显著性差异,综合炸荚检测的便利、安全及种子发芽率的影响,最终确定烘干温度60℃、持续时间11~13h为最佳检测条件。     

Physiological responses of chickpea genotypes to terminal drought in a Mediterranean-type environment

Two field experiments were carried out to investigate the effects of terminal drought on chickpea grown under water-limited conditions in the Mediterranean-climatic region of Western Australia. In the first experiment, five desi (small angular seeds) chickpeas and one kabuli (large round seeds) chickpea were grown in the field with and without irrigation after flowering. In the second experiment, two desi and two kabuli cultivars were grown in the field with either irrigation or under a rainout shelter during pod filling. Leaf water potential (Ψ_l), dry matter partitioning after pod set and yield components were measured in both experiments while growth before pod set, photosynthesis, pod water potential and leaf osmotic adjustment were measured in the first experiment only.

In the first experiment, total dry matter accumulation, water use, both in the pre- and post-podding phases, Ψ_l and photosynthesis did not vary among genotypes. In the rainfed plants, Ψ_l decreased below −3 MPa while photosynthesis decreased to about a tenth of its maximum at the start of seed filling. Osmotic adjustment varied significantly among genotypes. Although flowering commenced from about 100 days after sowing (DAS) in both experiments, pod set was delayed until 130–135 DAS in the first experiment, but started at 107 DAS in the second experiment. Water shortage reduced seed yield by 50 to 80%, due to a reduction in seed number and seed size. Apparent redistribution of stem and leaf dry matter during pod filling varied from 0 to 60% among genotypes, and suggests that this characteristic may be important for a high harvest index and seed yield in chickpea.     

遮阴对小麦生理和品质特性影响的研究进展

小麦是我国重要粮食作物之一,随着我国林下经济的迅速发展和气候变化造成太阳总辐射量的下降,筛选出合适的耐阴小麦品种和建立健全林下种植小麦的配套栽培技术成为当务之急。笔者总结了遮阴对小麦生理特性和籽粒品质影响的研究进展,讨论了适合遮阴条件种植的小麦品种应具有的生理特征和采取的栽培措施,指出遮阴处理后优选小麦叶片能维持较高的实际光化学效率(ΦPSⅡ)和抗氧化酶活性(清除O_2?和OH.活性氧自由基)等生理特征,以及灌浆速度快的小麦品种,施以垄作和合理氮肥运筹可以获取良好的经济效益。最后展望了小麦良种良法配套在林木、果树和小麦复合种植系统中的应用前景。     

2个小麦品种籽粒灌浆性状的分析

为了对小麦新品种的选育提供理论依据,利用Richards方程对小麦品种‘绵麦37’（四川省小麦新品种区域试验对照品种）和‘川麦42’（长江上游冬麦组品种区域试验对照品种）的灌浆性状进行了研究。研究得出了2个品种的主要灌浆性状参数,结果表明,在四川盆地,灌浆速率比灌浆持续时间更能影响小麦粒重,小麦粒重主要受灌浆前期和灌浆中期的灌浆速率的影响,灌浆中期对粒重的贡献达到45%以上。通过以上结果,认为在小麦新品种选育的实践中,要兼顾较长的灌浆持续期、较高的平均灌浆速率和最大灌浆速率、以及抗倒伏性等性状的选择。     

Effects of Low Temperature Treatment at Seedling Stage on Soybean Growth, Development and Final Yield

The after effect of continuous and variable chilling temperatures acting periodically for 7 days at seedling stage (day/night: 2/2°C, 5/5°C, 15/2°C, 15/5°C, 15/15°C and control–22/18°C) on growth, development and final yield of soybean cultivar Polan and Progres were investigated. The temperature decrease lengthened the duration of the vegetation period before flowering for both cultivars, which allowed compensation for the reduced–as an effect of chilling–rate of daily increments in the leaf area and the dry weight of the above-ground parts of the plants. The most important symptom of chilling treatment was a considerable increase in the number of axillary branches after flowering, which caused an increase in the dry weight of plants. The subsequent reaction of the growth of leaves to chilling at seedling stage was, after flowering, variety dependent. The area of leaves bigger at Polan or similar to control at Progres ensured good seed filling in an increased number of pods developed on axillary branches. Chill-induced delay in plants development allowed the avoidance of low temperature occurring during flowering in this experiment. This chilling during flowering was one of the reasons of worse-pod setting and reduction of seeds per pod number at control plants.     

基于改进的CTGC系统下不同CO2浓度对水稻生长发育的影响

为探索二氧化碳肥效作用对作物生长发育产量形成的长期影响及其在气候变化背景下的综合影响，验证改进后二氧化碳与温度梯度系统（CTGC）的精确性与可靠性，开展了水稻全生育期二氧化碳和温度梯度处理试验，测定了水稻生长发育及产量形成的反应，分析了环境因素对水稻生长发育的影响，并就试验系统原理和功能的改进做了说明。研究表明，处理小区水稻的籽粒灌浆增长和灌浆速率、干物质增长和增长速率显著增加，产量和生物产量显著增加，并且表现为随二氧化碳浓度与温度增高而增加的趋势。生物量增加尤以营养生长中后期旺盛表现最为明显，并使得水稻发育期略显延迟；处理小区水稻的经济系数比对照小区明显降低。表明二氧化碳与温度处理增加了水稻的生物量，二氧化碳肥效作用对水稻籽粒产量的提高具有潜力。     

Growth and Yield of Peanut as Influenced by Degree and Duration of Shading

Peanuts ( Arachis hypogaea L.) which are commonly grown in intercropping systems often suffer from shading caused by the associated crop. Through this study an attempt has been made to estimate the effect of different levels of shade at different growth stages on crop yield. Field experiments were laid out during monsoon and winter seasons of 1985 and 1986 by creating artificial shading up to 25 and 50 per cent of the day/natural light at flowering-pegging, pod filling and maturity stages of a Spanish bunch type peanut. Dry matter production has shown linear response to light intensity and due to 50 per cent shading it was reduced by 55 per cent. Vegetative growth rate during pod filling stage was very poor as a result of increase in shading at this stage. In shaded plants the nodulation was less and some reduction in chlorophyll content was also observed. However, oil content in kernel was not affected by shading. Shading caused significant reduction in pod number and kernel weight and thus there was decrease in pod yield. Flowering to pegging and pod filling stages seemed to be sensitive to shading while increase in shading at maturity stage did not cause any reduction in yield. It could be possible to obtain about 90 per cent pod yield by avoiding shading during flowering to pegging stage (45 DAS).     

中国北方主栽花生品种抗旱性鉴定与评价

人工控水条件下,通过盆栽试验,在花生植株的结荚期和饱果期, 测定29个品种(系)的株高、分枝数、生物累积量、叶片含水量和光合色素含量等与抗旱性有关的13个表型性状和生理生化指标,采用抗旱系数法和隶属函数值法,鉴定各性状指标水分胁迫下的抗旱性。结果表明,相同指标评价不同花生品种抗旱性时得出的结果不同,依此可将供试品种(系)划分为抗旱性强、中、弱和不抗旱4类,即供试品种中唐科8号、冀花2号、冀花4号、花育25、花育17、花育22、大唐油、花育21具有较强的抗旱能力;花育20、花育24、潍花6号、花育27、鲁花11、阜花11、阜花13、唐油4号、丰花1号和G2具有中等抗旱能力;具有较弱抗旱能力的品种(系)有16-8、阜花10号、M5、花育16和鲁花14;而花育19、花育23、丰花6号、潍花8号、M7和TE-2在结荚期和饱果期均无抗旱能力。水分胁迫至结荚期,除分枝数和类胡萝卜素外,其余各形态型状和生理生化指标及其综合D值均可作为鉴定品种(系)抗旱性的依据;水分胁迫至饱果期,只有叶面积与抗旱系数间的相关极显著。无论在结荚期或饱果期,综合D值可作为鉴定品种抗旱性的指标,单一指标均不能准确判定某品种(系)的抗旱性。     

Modification of Leaf Photosynthesis by Foliar Application of Aliphatic Alcohols

A decrease in net photosynthesis (P_n) in leaves of main shoot with age ( 7 -28 days after opening) at two stages of peanut ( Arachis hypogaea L. var. M-13 ) reproductive growth (70 and 90 DAS) is reported. P_n rate decreased with advance in age of leaves, the decline was rapid during peak period of pod filling (90 DAS). Foliar application with aliphatic alcohols, maintained the chlorophyll content and enhanced PEP carboxylase activity. The present studies suggest that aliphatic alcohols enhance functional capabilities of leaf for a larger duration and hence maintain the supply of photoassimilates to the developing kernels of peanut leading to increased yield.     

不同花生品种(系)荚果和子仁内源激素含量变化与干物质积累特征分析

以3个荚果和子仁生长发育正常的花生栽培品种(系)和种子皱缩变异品系05D677为材料,测定其荚果和子仁生长发育过程中激素含量与干物质积累变化特征,分析其内源激素含量变化与干物质积累关系,探讨变异品系05D677中内源激素含量变化对荚果和子仁生长发育的影响。主要结果如下：(1)果针入土24~60 d是荚果和子仁干物质快速积累期,期间山花15、05D610和白沙1016荚果干物质积累速率(_PK_W)平均值与子仁干物质积累速率(_KK_W)平均值均极显著大于05D677;3个正常品种(系)_PK_W和_KK_W最大值均出现在果针入土30 d,05D677出现在果针入土36 d。(2)4个品种(系)幼果或子仁内细胞分裂素(Z+ZR)、赤霉素(GA)、生长素(IAA)、脱落酸(ABA)含量变化趋势基本相同,其中05D677的GA含量峰值出现时间比3个正常品种(系)晚6 d;05D677的Z+ZR、GA、ABA含量最高值均极显著低于3个正常品种(系),其IAA含量最高值极显著高于3个正常品种(系)。(3)荚果膨大中后期,_PK_W和_KK_W与Z+ZR、GA、ABA含量呈极显著正相关,与IAA呈极显著负相关;荚果充实初期,Z+ZR含量与_PK_W和_KK_W呈极显著正相关;GA含量在荚果充实后期和成熟期与_PK_W呈极显著正相关;ABA含量在荚果充实后期与_PK_W和_KK_W均呈极显著负相关,在成熟期与_PK_W呈极显著正相关。(4)与3个荚果和子仁发育正常的品种(系)相比较,05D677幼果迅速膨大期和子仁充实初期的IAA含量明显升高,且Z+ZR、GA和ABA含量不足可能引起内源激素比例失衡,影响荚果和子仁的生长,致使荚果和子仁发育进程延迟、干物质积累速率的极显著降低,表现为收获时荚果充实度差,种子皱缩。     

Transfer of the Kosena Rfk1 gene,required in hybrid seed production,from oilseed rape to turnip rape

Radiant frost is a major abiotic stress, and one of the principal limiting factors for agricultural production worldwide, including Australia. Legumes, including field pea, faba bean, lentil and chickpea, are very sensitive to chilling and freezing temperatures, particularly at the flowering, early pod formation and seed filling stages. Radiant frost events occur when plants and soil absorb the sunlight during the day time and radiate heat during the night when the sky is clear and the air is still. Dense chilled air settles into the lowest areas of the canopy, where the most serious frost damage occurs. The cold air causes nucleation of the intracellular fluid in plant tissues and the subsequent rupturing of the plasma membrane. Among the cool season grain legume crops, chickpea, lentil and faba bean and field pea are the most susceptible to radiant frost injury during the reproductive stages. The more sensitive stages are flowering and podding. Frost at the reproductive stage results in flower abortion, poor pod set and impaired pod filling, leading to a drastic reduction in yield and quality. In contrast, in the UK and European countries, frost stress is related to the vegetative stages and, in particular, the effects of frost have been studied on cotyledon, uni/tri-foliolate leaf and seedling stages during the first few weeks of growth. Few winter genotypes have been identified as frost tolerant at vegetative stages. Vegetative frost tolerance is not related to reproductive frost tolerance, and hybrids from the vegetative frost-tolerant genotypes may not necessarily be tolerant at the reproductive stage. Tolerance to radiant frost has an inverse relationship with plant age. In the field, frost tolerance decreases from the vegetative stage to reproductive stage. Unlike wheat and barley, it is difficult to analyse and score frost damage in grain legume crops due to the presence of various phenophases on one plant at the reproductive stage. The extent of frost damage depends on the specific phenophases on a particular plant. However, current studies on genetic transformation of cold tolerant gene(s), membrane modifications, anti-freeze substances and ice nucleating or inhibiting agents provide useful information to improve our current understanding on frost damage and related mechanisms. The effects of frost damage on yield and grain quality illustrate the significance of this area of research. This review discusses the problem of radiant frost damage to cool season legumes in Australia and the associated research that has been carried out to combat this problem locally and worldwide. The available literature varies between species, specific climatic conditions and origin.     

CO2浓度升高对春小麦灌浆特性及产量的影响

为给在大气CO2浓度升高条件下春小麦高产栽培提供理论依据,利用农田开放式空气CO2浓度增高（Free Air CO2Enrichment,FACE）研究平台,以春小麦‘定西24号’为供试品种,研究了大气CO2浓度升高对春小麦灌浆特性及产量的影响。结果表明,随着CO2浓度的增加,春小麦干物质积累增加,最大积累速率出现的时间推迟,最大积累速率增大。随着CO2浓度的增加,千粒重增加,最大灌浆速率出现的日期推迟,最大灌浆速率升高;在不同CO2浓度条件下,灌浆速率与粒重呈显著正相关,但灌浆持续期天数与粒重关系不大。从灌浆的3个阶段来看,渐增期持续时间和渐增期灌浆速率对千粒重的影响作用更大;CO2处理小麦的籽粒产量分别比对照提高了15.62%、29.42%和36.98%,平均增产27.34%,均达极显著水平。本试验中CO2处理使春小麦显著增产主要是由于每穗粒数显著增加的缘故。     

不同温度下灌浆期水稻籽粒内源激素含量的动态变化

利用人工气候箱设置高温(日均温度32℃)和适温(日均温度22℃)2个处理，对籽粒灌浆过程中4种主要内源激素（IAA、ZR、GA₃和ABA）含量差异及其动态变化作了比较分析。结果表明，高温对籽粒灌浆的影响主要表现为加速早期灌浆和缩短持续时间。在水稻灌浆初期，高温处理下籽粒IAA、ZR、GA₃含量明显低于适温处理，而灌浆中、后期的处理间差异较小；温度处理对籽粒ABA含量的影响尤为显著，整个灌浆期均呈高温处理明显高于适温处理的基本趋势；2个供试品种在不同温度处理下的4种内源激素含量变化存在着一定差异，其变化与品种的灌浆动态有关。高温下灌浆前期籽粒中IAA、ZR、GA₃含量的降低，尤其是ABA含量的剧增，可能是其早期灌浆加速及灌浆持续时间缩短的主要原因。     

Flowering, Pod Set and Reproductive Success in Soya Bean

Much of the variation in yield of soya bean [Glycine max (L.) Merrill] and other grain crops is associated with changes in the number of pods and seeds per unit area. Photosynthesis and seed characteristics are the primary determinants of pod and seed number, but recent research suggests that the temporal distribution of flower production may also play an important role. Soya bean has a long flowering period (up to 40 days or more), but most of the flowers are produced in a much shorter time. The length of the period varies among cultivars, growth habits (indeterminate and determinate) and environments. The reproductive success of flowers produced early in the period is usually greater than those produced later. Little is known, however, of the regulation of the temporal distribution of flower production or its potential role in determining pod and seed number at maturity. Research is needed to determine first, if the temporal distribution can be manipulated to increase pod and seed set and secondly, if such increases would result in higher yields.     

贵州高原夏秋麦籽粒灌浆特性的研究

本文据１９９２－１９９５年试验结果,以Ｌｏｇｉｓｔｉｃ方程拟合贵州高原不同夏秋麦品种的籽粒灌浆过程并计算出有关籽粒灌浆参数,发现不同夏秋小麦品种灌浆特性有所不同。通径分析灌浆参数与千粒重的表明,籽粒平均灌浆速度和最大灌浆速度是影响夏秋麦千粒重的两个主要因素。且两因素间有极显著相关。进一步分析发现,缓增期和渐增期日数以及快增灌浆速率对千粒重作用显著;缓增期日数与渐增期日数间有极显著负相关,快增期灌浆     

Effect of Nitrogen and Water Management on Panicle Development and Milling Quality of California Rice (Oryza sativa L.)

Nitrogen fertilization and water management are the most important agronomic factors in determining the yield and milling quality of rice. Yet little information is available on the effect of nitrogen and time of drainage on the uniformity of rice grain development on a panicle. The objectives of this study are 1) to evaluate the effect of nitrogen application on the uniformity of grain development on a panicle, and 2) to determine the combined effect of time of drainage and nitrogen application on rice yield and milling quality. Results show that nitrogen has a significant effect on grain filling characteristics. Nitrogen reduces grain filling rate, increases duration of grain filling, increases tiller numbers and decreases grain weight. The time of drainage is critical to the recovery of head rice. Generally speaking, late drainage tends to increase the head rice recovery, and its impact on rice milling quality is increased with an increased rate of nitrogen application.