Relationship between Carbon Isotope Discrimination, Ash Content and Grain Yield in Wheat in the Peninsular Zone of India

Carbon isotope discrimination (Δ) and ash content (m_a) have been proposed as indirect selection criteria for grain yield in wheat. The associations between Δ, m_a and grain yield were found, however, to depend highly on the environmental conditions, the organ sampled and the time of sampling. In this study, carried out in the warm conditions of the Peninsular Zone of India, the relationship between Δ, m_a and yield was studied in 30 bread and durum wheat cultivars under residual soil moisture stress (RSMS), post‐anthesis water stress (PAWS) and well‐watered (WW) conditions. Both Δ and m_a were analysed in young seedlings (four‐leaf stage), leaves at anthesis and grain at maturity. Ash content was also evaluated in leaves at booting stage and maturity. Grain Δ was lower under PAWS and RSMS than under WW, while seedling and leaf Δ did not significantly differ among water regimes. Grain yield was positively correlated to grain Δ under PAWS and negatively correlated to grain m_a under RSMS. A significant positive correlation was noted under RSMS and WW treatments between m_aL_m and grain yield. Ash content in leaf at maturity consequently appears to be a useful indirect selection criterion in environments where Δ does not show any correlation with yield. The results highlight the potential of Δ and m_a as indirect selection criteria for wheat yield in the conditions of the Peninsular Zone of India.     

Inheritance of growth vigour and its association with other characters in chickpea

Growth vigour plays an important role in the establishment of a normal crop. The F₂ population of a cross between high‐ and low‐growth vigour varieties of chickpea segregated into 15 high : 1 low growth vigour. The results for recombinant inbred lines and BC1P₂ showed a good fit to the expected 3 : 1 ratio. The results indicated that growth vigour is controlled by two genes with duplicate dominant epistasis. No gene has so far been identified for growth vigour in chickpea. Correlation between growth vigour and other characters showed that high growth vigour had significant negative correlation with days to first flower, days to 50% flowering, days to first pod and days to maturity.     

灌浆期高温胁迫对冬小麦叶源、库器官生理活性的影响及调控

研究了灌浆期高温胁迫条件对冬小麦叶源、库器官某些生理指标的影响。结果表明 ,高温胁迫导致冬小麦叶源、库活性显著降低。高温胁迫能显著降低冬小麦子粒蔗糖酶的活性 ,降低子粒可溶性糖含量 ,胁迫发生初期子粒ATP酶的活性迅速降低 ;高温胁迫导致冬小麦的旗叶MDA含量、脯氨酸含量上升。适当的调节剂处理能显著改变高温胁迫条件下上述生理指标的变化动态 ,显著抑制高温胁迫条件下冬小麦旗叶光合性能的下降 ,延缓叶片衰老的进程 ,对保持叶源、库器官的生理活性有显著的作用 ,协调源库关系 ,降低高温胁迫对植株的伤害程度     

Barley mutants with increased tolerance to aluminium toxicity

Acid soil and associated aluminium toxicity are considered as the number one abiotic factor limiting crop production. Over 2 billion hectares of acid soils exist world-wide, both in tropical and moderate climatic zones. In Poland acid soils represent up to60% of arable land. At soil pH < 5.0 Al ions become soluble in water and toxic to plants. Genetic improvement of Al tolerance in crops is the only alternative to soil liming, a traditional but short term and expensive agricultural cure to raise soil pH. Of the various cereals, barley is the most sensitive to Al toxicity. The known sources of Al tolerance in barley are limited to old cultivars and landraces. While they represent multiple alleles of a single locus, there is no potential to improve Al tolerance through recombination of non-allelic additive genes. In the Department of Genetics, Silesian University we have employed induced mutations for rapid creation of variability for Al tolerance in barley. Thirteen mutants with increased levels of tolerance to Al toxicity have been selected in M₃ generation after mutagenic treatment of four barley varieties with N-methyl-N-nitroso urea (MNH) and sodium azide. Six further Al tolerant mutants were identified in the collection of semi-dwarf mutants of the Department. All selected mutants confirmed Al tolerance with the use of three different methods of screening, i.e., root re-growth, root tolerance index and hematoxylin staining. Fourteen mutants exhibited significant root re-growth after 48 hour incubation with 3 ppm Al⁺³ and two of them, namely RL819/2 and RL820/6 were tolerant even to 6 ppm Al⁺³. Crosses of two selected mutants with their respective parent varieties indicated that Al tolerance in each mutant was controlled by a single recessive gene. Out of three methods tested, the root re-growth method facilitated by hematoxylin staining proved to be the most reliable technique for large scale testing. Double treatment with MNH or combined treatment with sodium azide and MNH and 6hinter-incubation germination between treatments were the most successful treatment combinations for induction of aluminium tolerance in barley. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effect of Water Stress on Physiological Attributes and their Relationship with Growth and Yield of Wheat Cultivars at Different Stages

The effects of water stress on physiological attributes of drought‐sensitive (Kalyansona) and drought‐tolerant (C‐306) wheat cultivars were studied in a pot experiment. Water stress was imposed by withholding irrigation at boot and anthesis stages. Leaf water potential, leaf osmotic potential and leaf turgor potential (measured with pressure chamber and osmometer), as well as leaf diffusive resistance, leaf transpiration rate and leaf‐to‐air transpiration gradient (measured with a steady‐state porometer) were measured diurnally. Growth and yield parameters were recorded after harvesting of the crop. Triplicate data were analysed using a completely randomized design and correlations amongst these parameters were computed. Water stress was found to reduce diurnal leaf water potential and leaf osmotic potential in both the genotypes but leaf osmotic potential was significantly higher in the drought‐tolerant cultivar C‐306 than in the drought‐sensitive cultivar Kalyansona. Positive turgor was recorded in both the genotypes under water stress and non‐stress conditions. Water‐stressed plants showed significantly lower turgor potential than control plants. In diurnal observations, water‐stressed plants exhibited significantly higher leaf diffusive resistance in both genotypes at both stages. The diffusive resistance of C‐306 was predominantly higher than that of Kalyansona. Water stress decreased leaf transpiration rate at both stages but the reduction was higher at the anthesis stage. The leaf‐to‐air temperature gradient was much higher in C‐306 than in Kalyansona at the boot stage but at the anthesis stage genotypic variation was non‐significant. The capacity to maintain cooler foliage was lower at the anthesis stage than at the boot stage in both the cultivars. Shoot dry weight, number of grains, test weight, grain yield, biological yield and harvest index decreased to a greater extent when water stress was imposed at the anthesis stage, while imposition of water stress at the boot stage caused a greater reduction in plant height and number of tillers. Similarly, water stress caused a smaller reduction in growth, yield and yield attributes in C‐306 than in Kalyansona. In general, the correlation coefficient of grain and biological yield with water potential and its components was positive and highly significant. Similarly, turgor potential was also correlated positively and significantly with grain yield at both the stages, but with biological yield it was significant only at the anthesis stage. A negative and significant correlation was obtained for diffusive resistance and leaf‐to‐air temperature gradient with grain yield at the boot and anthesis stages. The rate of transpiration was also positively and significantly correlated to grain and biological yields at both the stages. Amongst the yield attributes, number of leaves and number of tillers were positively correlated at the anthesis stage, whereas leaf area and shoot dry weight were significantly correlated with grain and biological yields at both the stages.     

Genotype by environment effects and selection for drought tolerance in tropical maize. II. Three-mode pattern analysis

A selection program in three tropical maize populations aimed to improve tolerance of mid-season to late season drought environments while maintaining grain yield (GY) potential. The selection process employed other attributes that included maintaining a constant anthesis date (AD) and, under drought, shortening the anthesis-silking interval (ASI) and increasing ear number per plant (EPP). Three-mode (genotypes × environments × attributes) pattern analysis, which consists of clustering and ordination, should be able to collectively interpret these changes from ten evaluation trials. Mixture maximum likelihood clustering identified four groups that indicated the populations' performance had changed with selection. Groups containing the advanced cycles of selection were higher yielding in most environments and had lower ASI and higher EPP, particularly in drought environments. Check entries with no selection for drought tolerance remained grouped with the initial cycles of selection. A 3 × 2 × 3 (genotypes by environments by attributes) principal component model explained 70% of the variation. For the first environmental component, ASI was shown to be highly negatively correlated with both GY and EPP while anthesis date (AD) was virtually uncorrelated with other traits. The second environmental component (explaining 10% of the variation) contrasted droughted and well-watered environments and showed that EPP and GY were better indicators of this contrast (in terms of changes in population performance) than were AD or ASI. Three-mode analysis demonstrated that improvements with selection occurred in both droughted and well-watered environments and clearly summarised the overall success of the breeding program. This revised version was published online in July 2006 with corrections to the Cover Date.     

转甜菜碱醛脱氢酶基因水稻种子萌发和苗期耐盐性的研究

用0.0、3.0、5.0g/L NaCl对2个转甜菜碱醛脱氢酶(BADH)基因水稻51-22、52-7与受体亲本中花8进行萌发期盐胁迫试验.结果表明,盐胁迫下转基因材料受抑程度小于受体亲本,尤以52-7表现明显.用0.0、3.0、5.0g/L NaCl对51-22、52-7和中花8在幼苗期进行14 d盐胁迫试验.结果表明,低盐胁迫时幼苗受盐害较小,高盐胁迫时转基因材料耐盐性优于受体亲本;在盐胁迫7 d后,转基因材料体内脯氨酸含量明显高于受体亲本,同一品种随盐度增大,脯氨酸含量升高.     

干旱胁迫诱导新疆野苹果细胞程序性死亡的细胞形态学研究

用聚乙二醇(Polyethylene glycol,PEG6000)处理新疆野苹果(Malus sieversii(Ledeb)Roem.)幼苗。通过对其叶片及根系中各细胞器的超微结构分析发现,干旱胁迫能诱导新疆野苹果发生细胞程序性死亡,并具有以下特点:随着干旱处理时间的延长,根系中各细胞器形态结构发生变化的时间普遍早于叶片;同是叶片,海绵组织中各细胞器形态结构发生变化的时间早于栅栏组织;同是根系,皮层细胞中各细胞器形态结构变化的时间普遍早于中柱细胞。     

不同浓度盐胁迫对转基因饲用甜菜种子萌发及幼苗生长的影响

通过不同浓度NaCl溶液处理转基因饲用甜菜种子及其幼苗试验，研究了盐胁迫下种子萌发、幼苗生长及胁迫解除后种子的效应，为盐土农业生产提供理论依据。结果表明，转基因饲用甜菜种子萌发的适宜Nacl浓度为50。150mmol/L，其中100mmoL／LNaCl胁迫下，种子发芽率最高，与对照相比高6．78％。随着盐胁迫浓度的升高，种子萌发延迟，萌发率也呈不同程度的降低。盐胁迫解除后，种子萌芽迅速，萌芽率提高，整齐度增加。转基因饲用甜菜幼苗在不同NaCl浓度胁迫下表现出的反应不同，高盐胁迫对抑制幼根生长影响较大。     

植物低温诱导蛋白和诱导基因研究新进展

本文就近年来植物低温诱导蛋白和低温诱导基因的研究进展进行了概述，同时探讨了低温诱导蛋白和低温诱导基因与植物抗寒能力之间的关系。