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1.
A. S. M. H. M. TALUKDER C. A. MEISNER M. A. R. SARKAR M. S. ISLAM K. D. SAYRE 《水稻科学》2014,21(2):99-107
Aerobic rice （Oryza sativa L.） cultivation is considered an alternative production system to combat increased water scarcity and arsenic （As） contamination in the food chain. Pot experiments were conducted at the Wheat Research Centre, Dinajpur, Bangladesh to examine the role of water management （WM）, As and phosphorus （P） on yield and yield attributes of boro （variety BRRI dhan 29） and aman （variety BRRI dhan 32） rice. A total of 18 treatment combinations of the three levels of As （0, 20 and 40 mg/kg） and P （0, 12.5 and 25.0 mg/kg） and two WM strategies （aerobic and anaerobic） were investigated. Yield attributes were significantly affected by increasing As levels. Grain yields of BRRI dhan 29 and BRRI dhan 32 were reduced from 63.0 to 7.7 and 35.0 to 16.5 g/pot with increasing As application, respectively, indicating a greater sensitivity of BRRI dhan 29 than BRRI dhan 32. Moreover, As toxicity was reduced with aerobic compared to anaerobic WM for all P levels. During early growth stages, phytotoxic symptoms appeared on BRRI dhan 29 and BRRI dhan 32 rice stems with increasing As levels without applying P under anaerobic WM. Under anaerobic and As-contaminated conditions, BRRI dhan 29 was highly susceptible to straighthead, which dramatically reduced grain yields. There were significant relationships between the number of effective tillers per pot and root dry weight, grain yield, and number of fertile and unfertile grains per pot for both BRRI dhan 29 and BRRI dhan 32 （P＆lt;0.001）. Our findings indicate that rice could be grown aerobically in As-contaminated areas with a reduced risk of As toxicity and yield loss. 相似文献
2.
《水稻科学》2017,(3)
In order to elucidate the role of antioxidant responses in salinity tolerance in rice genotypes under salt stress, experiments were conducted using four rice varieties, including salt-sensitive BRRI dhan 28 and three salt-tolerant varieties BRRI dhan 47, BINA dhan 8 and BINA dhan 10. Thirty-day-old rice seedlings were transplanted into pots. At the active tillering stage(35 d after transplanting), plants were exposed to different salinity levels(0, 20, 40 and 60 mmol/L NaCl). Salt stress caused a significant reduction in growth for all the rice genotypes. Growth reduction was higher in the salt-sensitive genotype than in the salt-tolerant ones, and BINA dhan 10 showed higher salt tolerance in all measured physiological parameters. The reduction in shoot and root biomass was found to be minimal in BINA dhan 10. Chlorophyll content significantly decreased under salt stress except for BINA dhan 10. Proline content significantly increased in salt-tolerant rice genotypes with increased salt concentration, and the highest proline content was obtained from BINA dhan 10 under salt stress. Catalase and ascorbate peroxidase activities significantly decreased in salt-sensitive genotype whereas significantly increased in salt-tolerant ones with increasing salt concentration. However, salt stress significantly decreased guaiacol peroxidase activity in all the rice genotypes irrespective of salt tolerance. K~+/Na~+ ratio also significantly decreased in shoots and roots of all the rice genotypes. The salt-tolerant genotype BINA dhan 10 maintained higher levels of chlorophyll and proline contents as well as catalase and ascorbate peroxidase activities under salt stress, thus, this might be the underlying mechanism for salt tolerance. 相似文献
3.
The present study evaluated submergence responses in 88 lowland indigenous rice(Oryza sativa L.) landraces from Koraput, India, to identify submergence-tolerant rice genotypes. In pot experiments, variations in survival rate, shoot elongation, relative growth index, dry matter, chlorophyll, soluble sugar and starch contents were evaluated in two consecutive years under well-drained and completely submerged conditions. Principal component analysis showed that the first three axes contributed 96.820% of the total variation among the landraces, indicating wide variation between genotypes. Major traits such as survival rate, relative growth index, soluble sugar and starch contents appeared to be important determinants of phenotypic diversity among the landraces. Phenotypic coefficient of variance was higher than genotypic coefficient of variance for all the traits and all showed high heritability(90.38%–99.54%). Five rice landraces(Samudrabali, Basnamundi, Gadaba, Surudaka and Dokarakuji) were the most tolerant to submergence. When submerged for up to 14 d, Samudrabali, Basnamundi and Godoba were notable for having greater survival rates than a standard submergence tolerant variety FR13 A, and also notable for elongating more vigorously and accumulating more biomass. These three landraces may therefore be especially useful in lowland rice growing areas that are affected by both moderate stagnant water and flash flooding. Molecular genotyping revealed that the submergence tolerance of Samudrabali, Basnamundi and Godoba is linked to the presence of one or more different Sub1 loci and it may well prove useful for breeding improved submergence tolerant rice varieties, thereby assising to improve yield stability in the rainfed lowland agro-ecosystem. 相似文献
4.
Flooding is one of the most hazardous natural disasters and a major stress constraint to rice production throughout the world,which results in huge economic loss.Approximately one-fourth of the global rice crops(approximately 40 million hectares)are grown in rainfed lowland plots that are prone to seasonal flooding.A great progress has been made during last two decades in our understanding of the mechanisms involved in adaptation and tolerance to flooding/submergence in rice.In this review,we summarized the physiological and molecular mechanisms that contribute to tolerance of flooding/submergence in rice.We also covered various features of flooding stress with special reference to rice plants,viz.different types of flooding stress,environmental characterisation of flood water,impact of flooding stress on rice plant and their morphological,physiological and metabolic responses under flooding.A brief discussion on the tolerance mechanism in rice exhibited to different types of flooding will be focused for the future crop improvement programme for development of flooding tolerant rice variety. 相似文献
5.
Crop domestication and thereafter gradual selection or directional breeding have narrowed the genetic diversity of elite varieties and even promoted gathering of deleterious mutations in their stress response mechanisms, whereas local ecotypes, landraces and wild relatives still growing on native environment and preferences keep the genetic diversities for features like stress tolerance. Rayada is such an exceptional ecotype, variant of typical deepwater rice, completely endemic to certain areas of Madhumati river tracts of Bangladesh and still shares some features of wild rices. Multiple physiological features of Rayadas are distinctly different from typical deepwater rice. Tolerance to prolonged flood, submergence and cold are special features along with strong photoperiod sensitivity and lack of dormancy. Moreover, longer root system and prompt recovery capacity make it as an elite resource of stress tolerance. However, it has long been neglected because of mainly its long life cycle and poor yield. This review examines the specialty of Rayada rice and the potential use of its unique traits. 相似文献
6.
以亚洲大豆育成品种为对象,评价其幼苗期耐淹性,揭示其遗传变异特点,从而为耐涝育种提供种质基础。采用我国黄淮、南方及亚洲其它15国的350份大豆育成品种,以相对死苗率为主要鉴定指标,结合叶片相对失绿率与相对萎蔫率,在苗期进行大豆耐淹性盆栽鉴定。结果表明:以相对死苗率为主的指标体系可以有效鉴定大豆品种的苗期耐涝性。亚洲品种群体存在丰富的耐淹性遗传变异,相对死苗率变幅为4.8%~212.0%。中国黄淮、中国南方、东亚、东南亚和南亚5个区域的品种均呈现中间多、两头少的单峰态分布,遗传变异系数均高于21.24%,耐淹性变异丰富,尤其中国黄淮地区覆盖了全群体相对死苗率变幅。各地区均存在耐淹品种,山东、江苏相对较多;从5个区域中依次优选出7、4、1、1、2,共15份耐淹性种质;系谱追踪发现莒选23、南农493-1、黔豆2号的耐淹性可能传递给后代;4份国外耐淹性品种兼具有抗病性可作为亲本拓宽中国耐涝育种的种质基础。 相似文献
7.
《水稻科学》2017,(4)
Single nucleotide polymorphisms and restriction digestion-based haplotype variations among 160 flood prone rice varieties were analyzed with enzymes Alu I and Cac8 I to generate polymorphisms at Sub1A and Sub1C loci(conferring submergence tolerance), respectively. Haplotype associated with phenotype was used to study the haplotype variations at Sub1A and Sub1C loci and to determine their functional influence on submergence tolerance and stem elongation. Three patterns at Sub1A locus, Sub1A0(null allele), Sub1A1(does not cut) and Sub1A2(one SNP), and four patterns at Sub1C locus, Sub1C1, Sub1C2,Sub1C3 and Sub1C4, were generated. Both tolerant Sub1A1 and intolerant Sub1A2 had the same length, but the difference was presence of a restriction site in the Sub1A2, but absent at the Sub1A1. Further, two types of polymorphism were detected at the Sub1C, one included major length polymorphisms(165, 170 and 175 bp) and the other was a single restriction site at different position. Eight haplotypes(different combinations of the two loci), A1C1, A1C2, A1C4, A2C2, A2C4, A0C2, A0C3 and A0C4, were detected among 160 varieties. Haplotype A1C1 was comparatively more related to haplotypes A1C2 and A1C4, having the same Sub1A allele, and these haplotypes were found only in Bangladeshi, Sri Lankan and Indian varieties. Most tolerant varieties in A1C1 haplotype showed slow elongation, having tolerant specific Sub1A1 and Sub1C1 alleles. Further, the varieties Madabaru and Kottamali(A2C2) also showed moderate level of tolerance without Sub1A1 allele. These varieties were different with FR13 A and also suspected to carry different novel tolerant genes at other loci. These materials could be used for hybridization with Sub1varieties for pyramiding additional tolerant specific alleles into a single genotype for improving submergence tolerance in rice. 相似文献
8.
Longer-term partial stagnant flooding, particularly when it occurs following transient complete submergence causes severe damage to modern rice varieties. Progress was made in developing varieties tolerant of complete submergence through transfer of the Submergence-1 (SUB1) gene into popular varieties. However, SUB1 may not be effective under partial stagnant flooding (SF), as the new varieties may not elongate and continue growth when fully or partially submerged because of the SUB1-mediated suppression of elongation. We tested a set of rice genotypes, including a pair of near-isogenic lines (NILs), Swarna and Swarna-Sub1, under either SF or SF following complete submergence of 12 d. Swarna-Sub1 had higher survival and yield than Swarna following 12 d of submergence, but survival and grain yield of all lines decreased substantially when SF of 15-30 cm followed complete submergence, with the sensitive lines experiencing greater reductions in growth and yield. This suggests the importance of combining SUB1 with tolerance of SF in areas where both stresses are expected during the season. Swarna and Swarna-Sub1 are more sensitive to long-term partial SF than IR49830 and IR42 because of their short stature, and Swarna-Sub1 showed slightly higher reduction in tillering than did Swarna when subjected to deeper SF alone, possibly because of further inhibition of elongation by SUB1 if induced in submerged tissue. The results suggest that tolerance of these genotypes to SF depends less on SUB1 introgression and more so on the genetic background of the recipient genotype, with better performance of the genotypes that are inherently taller, such as IR42 and IR49830. The SUB1 donor landrace FR13A and its derivative breeding line IR49830 had better survival and relatively less reduction in grain yield under SF following complete submergence and under longer-term partial SF, indicating that these genotypes may have genes other than SUB1 for submergence and SF tolerance. For better adaptation to prolonged SF, SUB1 should be introgressed into genotypes that tolerate partial SF through better tillering ability and taller shoots, because SUB1 may not be effective in shorter genotypes, as it promotes survival of submerged plants by hindering shoot elongation to conserve energy reserves. Varieties combining tolerance of prolonged SF with SUB1 will have broader adaptation in flood-prone areas and greater impacts on yield stability. 相似文献
9.
淹涝条件下水温对水稻幼苗形态和生理的影响 总被引：1，自引：0，他引：1
为了研究淹涝水温对具有不同耐淹能力水稻材料形态和生理的影响,明确淹涝水温对水稻幼苗耐涝能力影响的机理,采用盆栽试验,选取导入耐淹基因的耐淹品种IR64Sub1和淹水敏感品种IR42以及耐淹能力较强的品种冈优725和泰优398,设计20℃和30℃两种水温进行淹水处理,淹水时间分为0,3,6,9和12d。结果表明较低淹水温度下,水中的溶氧量显著高于高水温处理;随着淹水时间延长,高水温处理溶氧量下降速度显著快于低水温处理。高水温条件下水稻幼苗株高增长率要显著高于低水温处理,虽然高水温处理下耐涝品种株高增长率也显著增加,但是增长量要显著低于其他材料。高水温处理水稻茎鞘内可溶性糖和淀粉消耗高于低水温处理,但随着淹水时间的延长两种温度处理间差异逐渐变小,较低的水温可以减少叶片叶绿素降解速率。因此,降低淹水温度可以提高淹水条件下水稻幼苗的成活率。以上结果揭示了低水温可以减少茎鞘的伸长,减少非结构性碳水化合物的消耗及叶绿素的降解,从而水稻淹涝后能维持较高的成活率。这些发现有助于理解较低洪涝水温下水稻存活更长时间的机理。 相似文献
10.
宁麦9号选育方法的探讨 总被引：5，自引：0，他引：5
宁麦９号是江苏省农科院以扬８９－１７为母本、西风为父本,采用集团选择法选育成而的高产、稳产小麦新品种。该方法早期（Ｆ２、Ｆ３、Ｆ４）以产量为主要选择指标,以组合为单位进行初步测产,有利于提高群体中高产基因型的筛选频率;Ｆ３、Ｆ４进行异地多点产量鉴定,有利于选出广适性品种;早期（Ｆ２～４）就按大田生产密度种植,有利于个性性状的真实表达,并可提高育种效率;后地高代材料进行多点产量和抗病（逆）性鉴定,同 相似文献
11.
《Journal of Crop Improvement》2013,27(1-2):97-111
Abstract A quantitative trait locus (QTL) for waterlogging tolerance has been identified in a northern cultivar Archer. In the current study, Archer was crossed with two southern elite soybean cultivars A5403 and P9641 to investigate the efficiency of marker-assisted selection and phenotypic selection for waterlogging tolerance and to assess the value of waterlogging tolerance for soybean yield improvement. Near-isogenic lines (NILs) were created using the linked simple sequence repeat (SSR) marker Sat_064 for the waterlogging tolerance QTL from each of the F6-derived populations. Concurrently, 103 and 67 recombinant inbred lines (RILs) were also generated from Archer × A5403 and Archer × P9641, respectively. Significant variations in seed yield or plant injury were observed among the NILs and RILs under waterlogging stress. The 29 most tolerant and 29 most sensitive NILs and RILs were selected on the basis of waterlogging injury ratings and evaluated under irrigated and waterlogged conditions in Arkansas and Missouri in 2002 and 2003. The most tolerant lines produced an average of 60.9% of their irrigated yield, as compared with only 32.6% and 53.9% by the most sensitive lines and the commercial checks, respectively. Waterlogging injury scores for the tolerant lines, checks, and sensitive lines were 3.6,4.3, and 6.6, respectively, following the same trend as their yield reductions. A genotype-by-environment interaction (G × E) analysis showed that some of the selected lines were highly stable in response to waterlogging stress across environments. Breeding selection for the waterlogging tolerance can be performed in the field based on seed yield and plant injury scores. 相似文献
12.
Arvind Kumar Jrme Bernier Satish Verulkar H.R. Lafitte G.N. Atlin 《Field Crops Research》2008,107(3):221-231
Drought is the most important constraint reducing rice yield in rainfed areas. Earlier efforts to improve rice yield under drought mainly focused on improving secondary traits because the broad-sense heritability (H) of grain yield under drought stress was assumed to be low, however gains in yield by selecting for secondary traits have not been clearly demonstrated in rice. In present study, the effectiveness of direct selection for grain yield was assessed under lowland reproductive stage stress at Raipur in eastern India and under upland reproductive stage drought stress at IRRI. The selection under severe stress (in both upland and lowland trials) resulted in greater gains under similar stress levels (yield reduction of 65% or greater under stress) in evaluation experiments than did selection under non-stress conditions, with no yield reduction under non-stress conditions. We observed similar H of grain yield under stress and non-stress conditions, indicating direct selection for yield under drought will be effective under both lowland and upland drought stresses. None of the secondary traits (panicle exsertion, harvest index, leaf rolling, leaf drying) included in our study showed a higher estimate for H than grain yield under stress. Secondary traits as well as indirect selection for grain yield under non-stress situation were predicted to be less effective in improving yield under drought in both lowland and upland ecosystem than direct selection for grain yield under the respective stress situations. The low, but positive values observed for genetic correlation (rG) between yield under stress and non-stress indicated that it is possible to combine drought tolerance with high-yield potential but low values also indicated that selection for grain yield needs to be carried under stress environments. The study also indicated that under lowland drought stress, the use of highly drought-tolerant donors, as parents in crosses to high yielding but susceptible varieties resulted in a much higher frequency of genotypes combining high-yield potential with tolerance than did crosses among elite lines with high-yield potential but poor tolerance. Breeding strategies that use drought-tolerant donors and that combine screening for yield under managed drought stress with screening for yield potential are likely to result in the development of improved cultivars for drought-prone rainfed rice producing areas. 相似文献
13.
《Plant Production Science》2013,16(3):316-323
AbstractRice plants are damaged by flash floods with a rapid increase in water level caused by a heavy rain. However, rice plants cope with the flash floods either by an “escape strategy” involving rapid shoot elongation or by a “quiescence strategy” involving surviving under water with minimal activity. As we found in previous experiments, Saligbeli cultivar adapted well to flash floods through rapid shoot elongation. To understand the vigorous growth process during submergence, we studied the relationship between shoot elongation and changes in dry matter weight (DMW) during submergence. O. glaberrima Steud. cv. Saligbeli and O. sativa L. cv. Ballawé and IR 49830-7-1-2-2 were used. Saligbeli and Ballawé exhibit shoot elongation, and IR 49830-7-1-2-2 exhibits flash-flood tolerance due to the presence of the Sub-1 gene. Twelve-day-old seedlings were submerged for 7 days and the plant length and DMW were measured. The plant length ratio of submerged to control plants in Saligbeli was higher than that of other cultivars during 2-6 days of submergence but IR 49830-7-1-2-2 shoot elongation was inhibited by submergence. In all three cultivars, the elongation of the developing leaf sheath conferred shoot elongation during submergence. The plant length of all submerged plants showed a strong positive correlation with DMW of the leaves developed during submergence. Submerged Saligbeli and Ballawé showed strong negative correlations between DMW of the leaves developed before and during submergence (r = –0.786 for Saligbeli and –0.772 for Ballawé , P < 0.05), suggesting that the enhancement of shoot elongation during submergence is accomplished by using dry matter of the leaves developed before submergence. However, the correlation was not observed in the submerged IR 49830-7-1-2-2. Further details from studies using isotopes are also needed to understand the plant growth during submergence. 相似文献
14.
甜菜耐丛根病品系ＮＣ－８是利用国外抗源,通过强化选择,不断提高含糖率,使之成为适合本地区种植的耐丛根病新品系。属标准型二倍体多粒种,根产量在甘肃河西地区平均达到５３．３１ｔ／ｈｍ＾２;产糖量平均达到８０５８ｋｇ／ｈｍ＾２;含糖率平均为１５．０％,分别较对照组提高２４８．４％、３８２．１％和３．４９个百分点。主要特点是耐丛根病性强、根产量高,在病田和无病田均能获得高产。适合于丛根病发生地区种植。 相似文献
15.
Simultaneous selection for seed and forage production in cocksfoot (Dactylis glomerata): application of drought tolerance and susceptibility indices 
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下载免费PDF全文 An experiment was conducted to estimate drought tolerance of some cocksfoot genotypes based on seed and forage yield and related indices (including tolerance index, mean productivity, geometric mean productivity, reduction percentage index, stress tolerance index and stress susceptibility index) and to identify relationships between measured traits. Twenty‐five genotypes were evaluated in the field under control and drought‐stress environments over 2 years. The results revealed a high variation for seed yield and forage yield and the measured indices under both moisture conditions. No correlation was observed between seed yield and forage yield under the control treatment, but this correlation was positively significant under the water‐stress treatment. Drought‐tolerant and susceptible genotypes were identified based on seed and forage yield performance. Genotypes 2, 4 and 7 had high seed yield, while genotypes 7 and 10 had high forage yield under both stressed and non‐stressed conditions and were identified as the most tolerant genotypes in each category. The results also revealed that genotypes 1, 2, 4, 6, 7, 8 and 24 had relatively high seed and forage yield in both control and drought‐stressed conditions. These genotypes can be used for further studies to improve both seed and forage yields concurrently. 相似文献
16.
《Plant Production Science》2013,16(4):395-400
AbstractWe evaluated the varietal difference in the flood tolerance of germinated seed in 17 Japanese varieties of common buckwheat (Fagopyrum esculentum Moench), including both local varieties and bred varieties or lines of different agroecotypes. Germinated seeds were flooded for 1 day in a growth chamber in June, July and August. The mean rate of seedling emergence from the seeds sown on different dates varied with the variety ranging from 20.4 to 57.4%. The mean emergence rate of summer agroecotypes (29.9%) was significantly lower than that of intermediate and late-summer agroecotypes (42.8 and 40.1%, respectively), and that of local varieties (44.2%) was significantly higher than that of bred varieties or lines (31.2%). These results suggest that inherent variation in flood tolerance was decreased by breeding as a result of a bottleneck effect. The local variety ‘Kitou zairai’, which exhibited a high and stable seedling emergence rate, may be a suitable choice in breeding for flood tolerance during germination. We also attempted to select for flood tolerance under mild selection pressure. Mass selection after four generations increased seedling emergence rate in five of six selected lines (with the exception of ‘Kitawasesoba’) compared with those of unselected populations, although the results varied with the line. These results indicate the possibility of breeding for flood tolerance during the germination period. 相似文献
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18.
早稻灌浆期淹水对剑叶理化特性及产量和品质的影响 总被引：2，自引：0，他引：2
以天优998和桂农占为试验材料,盆栽条件下在灌浆期进行2/3淹水和没顶淹水处理(淹水历时0 d、1 d、3 d、5 d和7 d,0 d为对照),对淹水后早稻剑叶理化特性以及产量和品质进行分析。 结果表明,灌浆期水稻在1 d~3 d短期2/3和没顶淹水后产量和品质显著下降,淹水5 d~7 d产量下降最为严重。有效穗数下降是淹水导致产量下降的主要因素。相同淹水条件下,两个水稻材料间产量和品质变化差异不显著。灌浆期水稻淹水后水稻剑叶的游离脯氨酸和MDA含量升高,SPAD值和SOD酶活性下降,随淹水深度和持续时间的延长变幅增大。灌浆期淹水后水稻剑叶SPAD值和MDA含量与产量和品质呈显著或极显著相关,是反映淹水后水稻产量和品质变化生理指标。 相似文献
19.