GENETICALLY MODIFIED AND CONVENTIONAL DRY BEAN GENOTYPE RESPONSES TO SOIL FERTILITY

Dry bean is important pulse for the diet of South American population and results related to comparison of genetically modified and conventional dry bean genotypes to soil fertility are limited. A greenhouse experiment was conducted to compare genetically modified and conventional dry bean genotypes to soil fertility. Genotypes evaluated were Olathe Pinto, Olathe 5.1 (genetically modified), BRS Pontal, BRS Pontal 5.1 (genetically modified), Pérola and Pérola 5.1 (genetically modified). Fertility levels were 1 g fertilizer (5-30-15) kg^?1 soil (low fertility level) and 2 g fertilizer (5-30-15) per kg soil (high fertility level). These fertility levels were designated as low and high, respectively. Grain yield, number of pods per plants, and seed per pod were significantly increased with the increase in soil fertility. Shoot dry weight, seed per pod, and 100 seed weight were also significantly influenced by genotype treatment. Fertility X genotypes interaction was significant for maximum root length and root dry weight, indicating genotypes responded differently at two fertility levels in relations to these two traits. Shoot dry weight, number of pods per plant, and grain harvest index had significant association with grain yield, indicating that increase in these three traits grain yield can be increased. Grain yield efficiency index (GYEI) was having significant linear association with grain yield. Hence, on the basis of GYEI, genotypes were classified as efficient (E), moderately efficient (ME), and inefficient in nutrient use. Three conventional genotypes (Olathe Pinto, BRS Pontal and Pérola) and one genetically modified genotype (Olathe Pinto 5.1) were classified as moderately efficient and two genetically modified genotypes (Pérola 5.1 and BRS Pontal 5.1) were classified as efficient. None of the genotypes fall into the inefficient group.     

Cadmium sulfate application to sludge‐amended soils: III. Relationship between treatment and plant available cadmium,zinc, and manganese1

Abstract

Swiss chard (Beta vulgarisvar. cicla) and corn (Zea maysL.) were used as biological indicators of Cd, Zn and Mn availability in 12 soils amended with and without sludge, CdSO₄and CaCO₃. Soil Cd, Zn and Mn were partitioned into six fractions: soluble, exchangeable, adsorbed, organically bound, carbonate bound and sulfide bound, by the use of H₂O, KNO₃, H₂O, NaOH, EDTA and HNO₃, respectively. The data indicate that the major portion of total Cd was found in the carbonate, residual and organic fractions. Addition of CaCO₃caused an increase in the soluble and exchangeable fractions of Cd in the soils. The concentrations of Cd in the saturation extracts of the limed soils were significantly greater than those of the unlimed soils; however, this was not reflected in greater plant uptake of Cd from limed soils.     

Investigations on the Relationship between Extracting (DTPA) Solutions and Plant (Phaseolus vulgaris) in the Uptake of Cadmium and Lead from Latosols

Given the relationship between the contents of heavy metals extracted from contaminated soil samples and dilution of these samples in diethylenetriaminepentacetic acid (DTPA) solution, the goal of this work was to test three soil–extractant solution ratios, namely 1:5, 1:10, and 1:15. The extracted contents from each solution were compared to those extracted by bean plants (Phaseolus vulgaris) cultivated in a greenhouse in two different soils: dystrophic red latosol (RLd) and humic red-yellow latosol (RYLh). Contents of cadmium (Cd) and lead (Pb) were greater in RYLh (lower amount of clay) for all soil–extractant ratios; 1:5 and 1:10 ratios differed negligibly from the plant result for the Cd extraction, while for Pb, the 1:15 soil–extractant ratio was the one that better correlated with the extractive behavior of sensitive indicator plants.     

The agronomic benefit of phosphate rock application with elemental sulfur depends on the reactivity and fertilizer placement

Abstract

A possible way to improve phosphate rock (PR) agronomic performance is through the addition of elemental sulfur (S⁰). We used ³²P isotope dilution method to assess the P taken up by crops treated with PR. Two experiments, one with common bean and other with upland rice, were carried out, to evaluate the effect of S⁰ on the agronomic performance of two contrasting PR, applied in different methods. Gafsa (GPR) and Patos de Minas (PPR) were used as the high and low reactivity PR, respectively. The experiments were arranged in completely randomized design on factorial structure 2?×?2 × 2?+?2; which means 2 PR (GPR and PPR) versus 2?S⁰ condition (with or without-S⁰) versus 2 application methods (band and broadcast) plus 2 additional treatments (control and triple superphosphate). In band application the S⁰ increased the amount of P uptake by plants from fertilizer of GPR from 2.57 to 9.86?mg pot^?1 for common bean and of 2.26 to 7.05?mg pot^?1 to rice. Regardless the management adopted, less than 2% of P applied as PPR has been taken up by crops. The addition of S⁰ as a strategy to increase the agronomic performance of PR is PR characteristics dependent and fertilizers placement.     

Relationships of Spectral Reflectance with Plant Tissue Mineral Elements of Common Bean (Phaseolus Vulgaris L.) Under Drought and Salinity Stresses

ABSTRACT

Salinity and drought stresses are critical for Phaseolus vulgaris L. growth and development. They affect plants in various ways, including tissue mineral element content. Micro- and macro-elements in leaves of Phaseolus vulgaris L. (cv. ‘Blue lake’ and cv. ‘Terli’) subjected to deficit irrigation and salinity treatments were investigated, both analytically and with regards to their effect on the leaves’ spectral reflectance. B (boron), K (potassium), Mn (manganese), Na (sodium), Si (silicon) and Zn (zinc) appeared to be influenced by stress factors, mainly responding to salinity increase. The leaf spectral reflectance of the plants appeared to be significantly correlated with most of the elements under investigation. Multivariate regression identified a relationship of the reflectance at particular regions of the spectrum with phosphorus and NDVI (normalized difference vegetation index) and indicated a significant correlation with B, Fe (iron), K, Mn, P (phosphorus) and Zn. Moreover, customized spectral indices, exhibiting significantly high correlation with B, Fe, K, Mg (magnesium), Mn, Na, P, Zn and N (nitrogen), were developed.     

Thiamine (vitamin B1) deficiency in germinating seeds of Phaseolus vulgaris L. exposed to soaking injury

Exogenous application of thiamine (vitamin B1) during imbibition improved germination and seedling development of bean (Phaseolus vulgaris L. cv. Lasso) seeds, which were exposed to soaking injury by submergence. Leaching of the vitamin into the incubation medium was not increased in submerged seeds. However, translocation of the thiamine reserves from the cotyledons to the seedling axis was reduced in response to soaking injury. After exogenous application of free thiamine to the seeds, thiaminedi-phosphate (TDP), which is the physiologically active coenzyme form of thiamine, accumulated in the seedling axis of submerged seeds, suggesting an increased demand for thiamine-dependent metabolic reactions in these tissues. Limited oxygen supply of the seeds during the soaking period induces a shift from respiration to fermentation of carbohydrates. Neither thiamine-dependent ethanolic fermentation, nor ATP production or adenylate energy charge (AEC) of the seedling axis were affected by exogenous thiamine application, suggesting that there is no limitation of thiamine-dependent reactions in the energy metabolism of the seedlings. Thus the physiological mechanisms improving germination and seedling development of submerged seeds in response to thiamine seed treatment are still not clear.     

低磷胁迫对不同基因型甜菜抗性生理特征的效应

选用对低磷胁迫抗性各异的3个甜菜品种:品20、品17和品14,在人工培养室内采用沙培试验法,研究了甜菜抗耐低磷胁迫的生理机制。结果表明,低磷胁迫限制了甜菜对磷的吸收,导致植株含磷量和生物产量显著下降;不同品种间差异显著,品14降幅最大,品17次之,品20最小。与足磷处理(P 100μmol/L)相比,低磷胁迫后甜菜品种间体内抗性生理特征差异显著。其中,品14和品17的丙二醛含量、脯氨酸含量、过氧化物酶活性均显著增加;品20的丙二醛含量、脯氨酸含量极显著下降,而过氧化物酶活性变化不显著。叶片中Mg2+-ATPase活性降低,不同品种降幅各异,从小到大依次为品20品17品14,其中品20与后两者间的差异均达显著。品20和品17体内的钙调素(CaM)含量显著增加,而品14变化不明显,其相对值从大到小依次为品20品17品14,差异显著,与品种自身抗磷胁迫能力顺序一致。不同磷素营养条件对甜菜抵御外界不良环境有较大影响,叶片在受到热伤害时,抗磷胁迫能力较弱的品14和品17在低磷胁迫时质膜损伤率显著增加;而抗磷胁迫能力较强的品20叶片质膜的损伤率显著下降,抗热能力得到改善。     

Interrelations between commercial beetroot (Beta vulgaris) cultivars and Meloidogyne species

Most beetroot (Beta vulgaris) cultivars in South Africa are exotic and were specifically bred for root-knot (Meloidogyne species) nematode populations in their countries of origin. Due to the widespread distribution of different Meloidogyne species and races, exotic cultivars should be matched with nematode populations in importing countries. The objective of this study was to determine the interrelations between exotic beetroot cultivars ‘Detroit Red Dark’ and ‘Crimson Globe’ with Meloidogyne species in the predominant beetroot-producing regions in South Africa. Different inoculum series of M. incognita and M. javanica were used on the two beetroot cultivars. At 56 days after initiating the treatments, roots of both cultivars had small undeveloped root galls, with the reproductive factor values of M. incognita on ‘Detroit Dark Red’ being above and below unity at low (≤125 inoculation) and high (≥250 inoculation) nematode levels, respectively. Growth of ‘Detroit Dark Red’ was significantly stimulated and inhibited at low and high nematode infection levels, respectively. In contrast, RF values for M. javanica on ‘Crimson Globe’ were below unity, without any significant effects on plant growth. In conclusion, ‘Detroit Dark Red’ was tolerant to M. incognita, whereas ‘Crimson Globe’ was resistant to M. javanica.     

Reduced titer of BNYVV in transgenic sugar beets expressing the BNYVV coat protein

Summary Rhizomania is a disease of sugar beet caused by the furovirus beet necrotic yellow vein virus (BNYVV). Coat protein mediated resistance has been reported for a number of viral diseases. This approach to virus resistance was therefore attempted for control of rhizomania. Two constructs of the coat protein gene of BNYVV were introduced into sugar beet by Agrobacterium-mediated transformation. The mRNA level was estimated to be 0.01% of the poly A⁺ RNA. Expression of the coat protein gene was under the detection limit of our western blotting protocol i.e. below 0.01 g/50 g (0.02% of the total soluble protein). One transformation event per construct was tested in a greenhouse assay and in rhizomania infested soil in a field trial. In the greenhouse assay, transgenic plants showed a strong reduction of virus multiplication when compared to non-transgenic plants. This result was confirmed in the field trial, where a significant difference in virus multiplication was shown between plants with and without the coat protein gene.     

Major genes for resistance to beet necrotic yellow vein virus (BNYVV) in Beta vulgaris

Summary Inheritance of resistance to beet necrotic yellow vein virus (BNYVV) was studied in segregating F2 and backcross families obtained from crosses between resistant plants of the sugar beet selection Holly-1-4 or the wild beet accession Beta vulgaris subsp. maritima WB42 and susceptible parents. Greenhouse tests were carried out, in which seedlings were grown in a mixture of sand and infested soil. Virus concentrations of BNYVV in the rootlets were estimated by ELISA. To discriminate resistant and susceptible plants, mixtures of normal distributions were fitted to log₁₀ virus concentrations, estimated for segregating F1, F2 and BC populations of both accessions. The hypothesis that Holly-1-4 contained one single dominant major gene was accepted. For WB42, results fitted with the hypotheses that resistance was based on either one (or more) dominant major gene(s) showing distorted segregation, or two complementary dominant genes, which are both required for resistance. Resistance from WB42 appeared to be more effective against BNYVV than resistance from Holly-1-4.This research was carried out as part of a PhD study at the Graduate School Experimental Plant Sciences (EPS), Department of Virology, Wageningen, The Netherlands