普通小麦-黑麦草(Lolium perenne L.)易位系鉴定及其后代灌浆与产量性状分析

为明确外源染色体或片段对小麦籽粒灌浆和产量性状的影响,以普通小麦宁春4号和黑麦草远缘杂交后代为材料,借助分子细胞学手段鉴定其BC1代染色体组成,并对其BC1F3代籽粒灌浆和产量性状进行了分析。结果表明,ND99株系出现两个顶端小片段易位类型的GISH杂交信号,为真杂种;ND99的BC1F3后代中分离出有芒(ND99A)和无芒(ND99B)两种类型,并且同一个分子标记3EST-185能够追踪这两种类型。宁春4号和易位系后代(ND99A、ND99B)籽粒的体积、鲜重、干重、水分均表现为先增后降的变化趋势;宁春4号和ND99A的灌浆速率呈双峰曲线变化,而ND99B呈多峰曲线变化。宁春4号的灌浆时间早,快速增长期长,籽粒饱满指数和粒重最大;ND99A灌浆迟,持续期短,籽粒饱满指数最低,粒重仅次于宁春4号;ND99B灌浆的峰值出现较早、较大,灌浆持续期短,籽粒饱满指数居中,粒重最低。易位系后代的穗长、穗粒数和结实小穗数明显高于宁春4号,可能是影响其灌浆的关键因素之一。     

Indirect changes associated with a selection program for increased seed-yield in wild species of Lesquerella (Brassicaceae): Are we developing a phenotype opposite to the expected ideotype?

Seed-yield stability, frequently associated with drought-tolerance strategies, is one of the main breeding objectives for the development of crops for semi-arid mediterranean-type environments. Since breeding of new industrial crops targeted for arid lands is not appreciably different from that of traditional crops, higher yield is achieved by increased harvest-index, at the cost of losing traits associated with drought-tolerance and reduced seed-yield stability. Using Lesquerella as a model we compared selected and unselected accessions of annual (L. gracilis and L. angustifolia) and perennial (L. pinetorum and L. mendocina) genotypes grown in field experiments in Patagonia, Argentina. Our objective was to assess the effects of breeding for increased seed-yield on traits related to the main characteristics that define the most common ideotype for mediterranean-type environments: early vigor, conservative growth strategy post-anthesis and reserves storage. Our specific question was: Have any of the attributes associated with seed-yield stability been indirectly selected during the domestication process? Our results show that these characteristics were reduced or lost, in selected lines compared to their wild relatives. Early vigor was lower in selected accessions and was associated mainly with reduced relative growth rate and CO₂ assimilation. During the reproductive period the growth strategy was changed by selection towards a non-conservative and more acquisitive resource use strategy. Traits associated with this strategy were linked to higher water use efficiency and growth capacity (higher CO₂ assimilation rate, specific leaf area, and leaf allocation), but also with loss of structural adaptation to low resource environments (i.e. low specific leaf area), an increase in nutrient and water demands, and reduced nutrient use efficiency. Carbohydrates accumulation pre-anthesis was lower in selected accessions of all four species, and also, just in perennials we found lower reserves storage post-anthesis. These changes in the pattern of carbohydrates accumulation could be associated to lower seed-yield stability due to the loss of buffer capacity linked with the use of pre-anthesis reserves for seed filling. On the other hand, in perennial species lower reserves storage after seed harvest could reduce plant longevity and survival. We conclude that indirect changes occurred during the preliminary domestication of both annual and perennial species of Lesquerella used in our experiment. These changes were against those required if these species were to be developed as crops for semi-arid, mediterranean environments and should result in low seed-yield stability.     

Will nutrient-efficient genotypes mine the soil? Effects of genetic differences in root architecture in common bean (Phaseolus vulgaris L.) on soil phosphorus depletion in a low-input agro-ecosystem in Central America

Crop genotypes with root traits permitting increased nutrient acquisition would increase yields in low fertility soils but have uncertain effects on soil fertility in the long term because of competing effects on nutrient removal vs. the soil conserving effects of greater crop biomass. This study evaluated the relative importance of phosphorus loss in crop extraction vs. phosphorus loss in soil erosion as influenced by genetic differences in root shallowness and therefore phosphorus uptake in common bean (Phaseolus vulgaris L.). Six recombinant inbred lines of varying root architecture and two commercial genotypes of bean were grown in unfertilized, steeply sloped (32%), low phosphorus (5.8 mg kg^?1, Fe-strip) Udults in Costa Rica. Fertilized (60 kg total phosphorus ha^?1) plots of commercial genotypes were also included in the study. Runoff was monitored throughout the bean growing season in 2005 and 2006, and in 2006, monitoring continued through the maize growing season. Phosphorus removed in plant biomass at harvest through the 2006 bean–maize crop cycle averaged 7.3 kg ha^?1 year^?1, greatly exceeding phosphorus loss due to erosion (0.15–0.53 kg ha^?1 year^?1) in unfertilized plots. In fertilized bean plots, total biomass phosphorus averaged 6.32 kg ha^?1 year^?1 and total eroded phosphorus averaged 0.038 kg ha^?1 year^?1, indicating rapid sorption of fertilizer phosphorus. Shoot growth of several recombinant inbred lines under low phosphorus was comparable to that of fertilized commercial genotypes, illustrating the effectiveness of selection for root traits for improving plant growth in low-phosphorus soils. Genotypic differences in root architecture of recombinant inbred lines led to 20–50% variation in groundcover by shoots, which was associated with 50–80% reduction in sediment loss. This study demonstrates that root architecture traits can affect nutrient cycling at the agro-ecosystem level, and that integrated nutrient management strategies are necessary to avoid soil nutrient depletion.     

Mapping of QTL for salt tolerance in rice (Oryza sativa L. ) via molecular markers

A recombination inbred (RI) population wasdeveloped by single seed decent from a combi-     

Integrating remotely sensed water stress factor with a crop growth model for winter wheat yield estimation in the North China Plain during 2008–2018

Accurate estimation of regional-scale crop yield under drought conditions allows farmers and agricultural agencies to make well-informed decisions and guide agronomic management. However, few studies have focused on using the crop model data assimilation(CMDA) method for regional-scale winter wheat yield estimation under drought stress and partial-irrigation conditions. In this study, we developed a CMDA framework to integrate remotely sensed water stress factor(MOD16 ET PET^-1) with t...     

RFLPmapping of a fertility restorer gene for rice (O. sativa L.) ′BT′ type CMS line

The Boro type (BT) cytoplasmic male sterility (CMS) line is the main CMS type for the utilization of heterosis in japonica rice. There is no restorer gene for BT CMS line in japonica rice and it was all from indica rice. The restorer gene used in China is from an IRRI indica variety, IR 8.     

RFLP mapping of a fertility restorer gene for rice(O.sativa L.)′BT′type CMS line

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Identification of a QTL for cold tolerance at early seedling stage via RFLP markers in rice （O. Sativa L. ）

Recently,beneficial genes in japonica and indica varieties were widely used from each other to promote the yield and insect and disease resistance,etc.in rice.Most indica varieties are susceptible to low temperature,and cold injury will affect the rice yield at various growth stages.     

Long-Term Reuse of Drainage Waters of Varying Salinities for Crop Irrigation in a Cotton-Safflower Rotation System in the San Joaquin Valley of California—A Nine Year Study: I. Cotton (Gossypium hirsutum L.)

Summary

Use of saline drainage water for crop irrigation was evaluated as a means of decreasing its volume. Results of a nine-year crop rotation (cotton-cotton-safflower, × 3) in which only the cotton was irrigated with drainage water of 400, 1,500, 3,000, 4,500, 6,000, and 9,000 ppm total dissolved salts are presented. The different salinity levels of irrigation waters were achieved by mixing nonsaline canal water (400 ppm) and saline drainage water. Cotton lint yields were not affected by increased salinity level of the irrigation water for the first two years. Detrimental effects became evident in the third cotton crop with increasing severity in later years. In the fifth year of cotton (seventh year of the study), lint yields were adversely affected by waters of salinity greater than 3,000 ppm. However, fiber quality remained unaffected at all levels of irrigation water salinity. The reductions in lint yield appeared to be a function of time and the salinity level of applied water. Shoot height and biomass were reduced by the irrigation water salinity before lint yields. Stand establishment appeared to be the most sensitive to salinity and was perhaps the main reason for yield reduction. Increase in irrigation water salinity increased Na⁺ content of leaf blades and petioles and decreased K⁺/Na⁺ ratio of leaf blades and petioles. The study showed that irrigation waters of up to 3,000 ppm salinity may be used for four years without any yield reductions, as long as some leaching occurs through preplant irrigations with low salinity water. Data on crop growth and development and ionic content collected over the nine year period are presented.     

Long-Term Reuse of Drainage Waters of Varying Salinities for Crop Irrigation in a Cotton-Safflower Rotation System in the San Joaquin Valley of California—A Nine Year Study: II. Safflower (Carthamus tinctorius L.)

Summary

This paper reports the results on safflower crops grown in a nine-year study, conducted on a 8 ha site, to determine the feasibility of using drainage water for irrigation in a 2-year cotton/1-year safflow-er rotation system. The cotton crops were irrigated with waters of 400, 1,500, 3,000, 4,500, 6,000, and 9,000 ppm total dissolved salts, and safflower was grown only with a preplant irrigation with nonsaline water. The use of drainage water for crop irrigation may be a means of decreasing its volume. Even though safflower was never irrigated with saline drainage water directly, the residual effect of using saline water for cotton irrigation adversely impacted safflower growth and development. Safflower seed yields were reduced in plots previously irrigated with waters of 4,500 ppm or higher salinity and even more severe effects on crop growth were seen as the numbers of years of irrigation with the saline water increased. After irrigating six cotton crops, the safflower seed yield in plots irrigated with 9,000 ppm waters was reduced to only 14% of the control. The safflower oil content and quality were not affected. Impacts on plant density, shoot height, shoot biomass, and leaf ionic content also are discussed.     

Alkaline phosphatase activity and its relationship to soil properties in a saline–sodic soil reclaimed by cropping wolfberry (Lycium barbarum L.) with drip irrigation

In order to ascertain the alkaline phosphatase (ALP) activity and its relationship with soil properties in saline–sodic soils during reclamation, a study was conducted in a saline–sodic soil reclaimed by cropping wolfberry (Lycium barbarum L.) with drip irrigation, in Ningxia Plain, Northwest China. The soil EC_e, pH and SAR in 0–30 cm were 12.3 dS m^?1, 9.4 and 44.1 (mmol/L)^0.5, respectively. Soil transects with different planting years were intensively sampled, which had a wide gradient of salinity and sodicity. Ranging from 1.1 to 42.4 μg g^?1 h^?1, soil ALP activities increased with the increasing planting years, and showed a large spatial variability within transect. The higher ALP activities were always found beneath the drip emitters. More soil physicochemical properties became related significantly to the ALP activities as the planting years increased, indicating that the ALP activities could be better predicted by other properties after reclamation. Path analyses showed that the negative direct effects of soil pH on ALP activities became clearly dominant as the planting years increased. The positive effects of organic matter on ALP activities exerted indirectly, mainly through pH, total N, and available P. Soil ALP activities decreased exponentially with pH, which varied from 7.38 to 10.00. Our findings demonstrated that soil pH was the limiting factor for improving soil ALP activities in this saline–sodic soil, and after three planting years, soil biological activities and fertility level increased significantly.     

Adaptation of the standard enzymatic protocol (Megazyme method) to microplaque format for β-(1,3)(1,4)-d-glucan determination in cereal based samples with a wide range of β-glucan content

The growing interest in β-glucans and the dietary recommendations of an exact daily intake will require rapid and accurate quantification methods of β-glucans that can be used routinely by the food industry. The objective of the present study was to adapt the standard enzymatic procedure (Megazyme method) to quantify (1-3)(1-4)-β-D-glucans to micro-plate format and further application to analyze cereal based samples with a wide range of (1-3)(1-4)-β-D-glucan content (from 0.27–75%). The samples used in this study included two breads (wheat and barley/wheat), barley flours (4% and 8% β-glucans) and two samples of oat bran (28% and 75% β-glucans). Results showed that there was no significant differences in the quantification of β-(1,3)(1,4)-D-glucans in different samples by using the Megazyme method or the micro-method. The methodology developed was also compared in terms of sensitivity and reproducibility with the results obtained by the Megazyme kit method and no differences were observed. In conclusion, the developed method allows the β-glucan quantification (specifically for mixed-linkage [(1-3)(1-4)]-β-D-glucan) to be conducted rapidly and by an efficient and sensitive micro-method in a wide range of concentrations.