Differences in reciprocal crosses of maize inbred lines diverse for protein content

Summary Forty-two crosses and their reciprocals in maize (Zea mays L.) involving inbred lines highly diverse for protein content were evaluated in four environments. Data were recorded on crude protein content of grain, protein yield, grain yield, 1000 kernel weight, dry matter content of ear at harves,, days to 50% slking, plant height, ear height, and early vigor. No significant variation due to reciprocal differences was observed for protein content and early vigor. For all other traits the variance component due to reciprocal x environment interactions was significant while the variance component due to reciprocal differences was significant only for kernel weight, dry matter content of ear, plant height, and ear height. The variance components due to nuclear differences and their interactions with environments were always highly significant and larger than the components due to reciprocal differences and reciprocal x environment interactions. The instability and low magnitude of reciprocal differences indicated that it might be difficult to exploit them commercially. However, seeing the presence of reciprocal differences for most of the traits studied, the evaluation of breeding materials for these differences seems to be important.The research work was supported by the Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 142.     

Selection for high self-incompatibility in inbred lines of brussels sprouts

Summary An attempt to improve the self-incompatibility of an advanced inbred line of Brussels sprouts by selection has been unsuccessful. The apparent plant-to-plant variation in self-incompatibility has little or no genetic basis. It results from environmental effects and from intrinsic physiological differences between flowers on a single plant. A temperature rise from 17°C to 26°C markedly increases the self-compatibility of the lines tested, but no evidence was found for end-of-season compatibility. The best methods for producing inbreds with high and consistent self-incompatibility are discussed.     

Rye introgression lines as source of alleles for pollen-fertility restoration in Pampa CMS

Restoration of pollen-fertility is required to guarantee successful seed production of hybrid varieties based on cytoplasmatic male-sterility (CMS) induced by Pampa cytoplasm. As most European restorer lines have still numerous disadvantages, using genetic resources via introgression libraries might be promising to identify and localize new and more effective restorer genes. The objectives of this study were to (1) evaluate in field trials the performance of 39 candidate introgression lines (pre-ILs) for pollen-fertility restoration and (2) to identify donor chromosome segments (DCS) underlying pollen-fertility restoration. Exotic alleles from the Iranian primitive rye accession Altevogt 14160 were introduced into the elite non-restorer inbred line L2053-N by marker-assisted backcrossing. BC₂S₃ pre-ILs were genotyped using amplified fragment length polymorphisms and simple sequence repeats. Pollen-fertility restoration was evaluated in replicated field trials across two testers at two locations in 2006 for analysing the phenotypic effects of the exotic DCS. Out of 39 pre-ILs, we determined three showing full pollen-fertility across both testers and locations carrying a DCS on chromosome 4R. Moreover, one pre-IL with partial pollen-fertility was detected showing a DCS on chromosome 1R. We conclude that our introgression library can serve as a valuable resource for mining favourable genes from exotic primitive rye, which can greatly promote hybrid rye breeding.     

Selection and genetic improvement of pollen fertility restorer lines with Triticum timopheevii cytoplasm in common wheat

The paper summarizes the selection and improvement of pollen fertility restoration in cytoplasmic male-sterile lines during the past 30 years at Jiangsu Province, China. A fertility restorer line (R16) with a good history of strong and stable restoring ability to different sterile lines was bred by accumulating fertility-restoring genes from derivatives of T797 and other restorer lines such as Primepi. A series of well-performing restorer lines with similar fertility-restoring ability has been bred by improving agronomic characters, disease-resistance and kernel size of R16. The restoring ability of these restorer lines using different male-sterile lines demonstrates that fertility restoration is no longer an obstacle for commercial utilization of hybrid wheat with the Triticum timopheeviii cytoplasmic male-sterile system. Line 2114 is a restorer with a single restoring gene transferred from Aegilops umbellulata. Its restoring ability, using both difficult and easily restored lines was 82% and 93.3% respectively. Maiyou No. 5, one hybrid variety, showed 13.2% yield advantage over the control variety in the Jiangsu Province registration test in 1997-1998 and was superior to nine other varieties adapted to the Jiangsu Province.     

Agronomic and quality characteristics of old,modern and mixture wheat varieties and landraces for organic bread chain in diverse environments of northern Italy

Wheat landraces and old varieties could have an important role for food security not only as source of gene readily available for breeders, but also because they perform well in marginal environments and are more resilient as compared to the modern cultivars. The Italian cereal sector suffers from lack of seed companies that breed specifically adapted varieties for organic and biodynamic farms. Participatory and evolutionary plant breeding (PPB and EPB) have been used in this research to (i) evaluate the agronomic characteristics of old, modern and mixture of varieties and landrace of bread wheat (Triticum aestivum spp.) and their adaptability to organic farming in hilly and mountainous areas; (ii) assess the technological, nutritional and functional properties of grains (rheological characteristic, macro and micro elements contents and antioxidants); (iii) explore the consumers’ preferences for breads obtained by old and modern varieties. Between five and seven old (Sieve, Verna, Gentil Rosso, Andriolo, Gambo di ferro, Frassineto and Abbondanza), two mixtures and four modern (Bolero, Blasco, Arabia and Bologna) varieties were tested for two years in between two and three organic farms (FARM1, FARM2 and FARM3) in hilly areas of Piedmont. Agronomic characteristic were strongly affected by locations and years. On average, Bologna, Abbondanza and Arabia, and the two mixtures were the highest yielding varieties. Flour strength (W) varied greatly ranging from 230 in 2011 for Andriolo to 38 in 2012 for Gambo di ferro. Gluten quality, expressed by GI, was found to be almost within the optimal range but was affected by the year. All six bread samples were acceptable to the 233 consumers who scored them, but the bread produced with old wheat varieties, particularly with Andriolo and Gambo di Ferro, was the preferred one. The old varieties and their mixtures yielded less than the modern varieties but with higher stability as shown by the inability of the modern varieties in FARM1 to survive the winter (they were not harvested) while the old varieties reached maturity showing higher robustness, Therefore, the use of old bread wheat varieties and their mixture, assessed with participatory and evolutionary plant breeding, could represent a strategy for local communities to cope with climate change while improving food security and food quality.     

Effectiveness of selection at CIMMYT's main maize breeding sites in Mexico for performance at sites in Africa and vice versa

The exchange of elite breeding materials across regions is an important way in which multinational maize breeding programmes access new genetic variation, improve efficiency and reduce costs. Our objectives were to examine whether CIMMYT's breeding programmes for tropical and subtropical environments in Mexico and Eastern and Southern Africa (ESA) can effectively share materials. Sets of selected and unselected lines were evaluated for per se and testcross performance in multiple environments in Mexico and ESA for grain yield, days to anthesis and plant height. Genotypic correlations between performance in Mexico and ESA as testcross and line per se were high (≥ 0.72) for all experiments, and indirect selection efficiency ranged from 67 to over 100% for all traits. Lines selected in ESA or Latin America performed equally well in each region, indicating selection was for broad rather than regional adaptation. Thus, breeding programmes of CIMMYT in both Mexico and ESA can benefit tremendously by exchanging breeding materials and test results, and elite selections from each region should be fast‐tracked for evaluation in the other.     

Influence of water availability on fertility restoration of CMS lines with the 'M35', A4 and '9E' CMS-inducing cytoplasms of sorghum

Male fertility restoration in new types of sorghum cytoplasmic male sterility‐inducing cytoplasms (A4, ‘9E’, ‘M35’), characterized by the formation of non‐dehiscent anthers, is difficult. Lines with fertility‐restorer genes for these unique cytoplasms do occur, but rarely, and when found tend to be unstable in their inheritance and expression. The aim of this research was to explore reasons for this instability. Seven lines in three unique cytoplasms, ‘9E’, A4 and ‘M35’, and six lines that restore with these cytoplasms were grown at the Agricultural Research Institute for South‐East Region in Saratov, Russia from 1993 to 2004. Levels of male fertility restoration and various environmental factors were recorded. It is reported that for sorghum hybrids in the A4, ‘9E’ and ‘M35’ male‐sterile cytoplasms, the level of plant male fertility is determined by the level of water available to plants during anther and pollen formation that which ‘switches on’ the expression of fertility‐restoring genes, and is possibly involved in an unusual type of male fertility inheritance in these cytoplasms. The creation of reliable line‐fertility restorers capable of the restoration of male fertility of F₁ hybrids in ‘M35’ cytoplasm under conditions of water stress is also reported. Current research explore mechanisms involved possible in responses to water levels at various growth stages and their influence on fertility within these cytoplasms.     

Selection for yield in Lolium perenne. II. performance of spaced plant selections under competitive conditions

Summary The performance of six lines of perennial ryegrass (Lolium perenne L.) which had been selected for three generations for production under spaced plant conditions were assessed under increasing levels of competition, namely spaced plants, drills, miniplots and large sown plots. Successful selection for yield under spaced plant conditions was not accompanied by comparable production patterns in the alternative managements. The extreme situation occurred in swards where a significant decline in production was encountered. Negative or no relationships were found in the establishment year between spaced plant production and yield in the alternative conditions whereas in the first harvest year positive correlations occurred between spaced plants, drills and miniplots and only the latter with plots. These varying patterns of performance are considered in relation to the prediction of sward behaviour and the appropriate environment for selection.INIA. CRIDA 01, La Coruna, Spain.     

Identification of the Rf gene conferring fertility restoration of the CMS Dian-type 1 in rice by using simple sequence repeat markers and advanced inbred lines of restorer and maintainer

Cytoplasmic male sterility of Dian‐type 1 (CMS‐D1) was developed 30 years ago in Yunnan. A major gene conferring fertility restoration for the CMS‐D1 system was detected by microsatellite markers in advanced inbred lines consisting of 196 maintainers and 62 restorers developed in breeding programmes of hybrid rice involving the CMS‐D1 system. The gene was mapped between two simple sequence repeat markers, OSR33 and RM228, on chromosome 10, and was temporarily designated as Rf‐D1(t). The genetic distances of the gene to the two microsatellite markers were 3.4 and 5.0 cM, respectively. This linkage was confirmed by using an F2 population derived from a cross between a CMS‐D1 line and a restorer. This study also demonstrated that using OSR33 was reliable and efficient for identification of restoring lines in hybrid rice breeding with the CMS‐D1 system.     

Variation of characters in near-isogenic lines of wheat with added genes for leaf rust resistance

Summary Using the cultivar Arina as the recurrent parent, six backcrosses were made with two donor lines carrying the leaf rust resistance genes Lr1 and Lr9, respectively. Selection for leaf rust resistance occurred at the seedling stage in the greenhouse; the first plants transferred to the field were BC₆F₄s. Frequency distribution of the 332 Lr1/7 × Arina and the 335 Lr9/7 × Arina lines showed continuous variation for yellow rust resistance and heading date in these leaf rust near-isogenic lines (NILs). Similar results were also obtained for plant height, for resistance to powdery mildew and glume blotch, as well as for baking quality characters in another set of more advanced NILs. The available information on the behaviour of one of the parents of cultivar Arina led to the conclusion that the expressed yellow rust resistance is quantitative and might possibly be durable.     

Evaluation of CropSyst for simulating the yield of flooded rice in northern Italy

Research on rice cropping systems carried out in Europe has to face the great variability of pedo-climatic conditions, and the linked abundance of cultivated varieties, characteristic of the high latitudes-temperate areas where rice is traditionally grown.

Dynamic simulation models can provide an useful tool for system analysis needed to improve the knowledge, the agronomic management and crop monitoring.

For calibrate and validate CropSyst (never used for rice), a process-based simulation model, for Indica-type and Japonica-type varieties, data obtained from five field experiments, carried out in Northern Italy between 1989 and 2002, were used.

Plants were sampled during the life cycle from rice plots of five cv Loto, Cripto, Ariete, Drago, Thaibonnet and Sillaro, maintained at potential production, to determine some important crop variables and parameters such as aboveground biomass (AGB), leaf area index, specific leaf area, harvest index, the date of the main phonological stages.

At the end of the calibration process to the parameters (the others were set to the default value, taken from the Literature or measured) optimum mean daily temperature for growth, specific leaf area (for Japonica varieties), stem/leaf partition coefficient (empirical), leaf duration, were assigned the following values: 28 and 27 °C respectively for Japonica and Indica varieties, 27 and 29.5 m² kg⁻¹ respectively for Japonica early and medium-late varieties, 4.5, 3, 1.5 for Japonica early, medium-late and Indica varieties, 700, 850, 950 °C-days for the three groups of varieties.

The assessment of model performances has shown average RRMSEs of 20 and 22% at the end of calibration and for the validation process; the modelling efficiency is always positive and the coefficient of determination always very close to 1. General improvements will be achieved by the model by considering the thermal profile (strongly influenced by flooding water at mid latitudes) evolving in and over the canopy.     

Prediction of hybrid performance based on the genetic distance of parental lines in two-line rice (Oryza sativa L.) hybrids

A total of six TGMS (thermosensitive genic male sterile lines) and nine pollinator lines were subjected to molecular characterization using 48 genome-wide SSR (simple sequence repeat) markers. Cluster analysis revealed clear differentiation among the TGMS lines according to their source of origin. The SSR-based genetic distance between the hybrids of the parental lines ranged from 0.36 to 0.79 suggesting a high degree of genetic divergence. Among a set of 54 hybrids generated using parental lines, 32 showed better parent heterosis (+21.7%) while 19 showed mid-parent heterosis (+15.0%). For the trait yield per plant genetic distance (GD) was negatively correlated with F₁ performance (r = ?0.202), mid-parent heterosis (r = ?0.325*; P < 0.05), and better parent heterosis (r = ?0.261), while it was positively correlated with specific combining ability (r = 0.042). Based on the grouped genetic distance (GGD), the hybrid combinations were divided into four groups. The GGD showed linear correlation with hybrid performance within the group (GGD = 40–50: r = ?0.07; GGD = 70–80: r = 0.32). This information can be utilized in the development of higher yielding, two-line rice hybrids through selection of intermediately diverse parental lines using GGD.     

Selection for resistance to the maize weevil in kernels of maize

Summary Significant differences in progeny numbers, weights and developmental periods of weevils were found among maize slections. Resistance to weevil attack increased through selection in dent types but not in flint types. Resistance was located in the pericarp, which is maternal tissue. In the nearly homozygous dent lines the pericarp and embryo are genetically similar. Lack of success in the selection for resistance in the flint sources is explained by the difference in genotypes between pericarp and embryo, as little inbreeding had occurred. Some degree of antibiosis was found in the endosperm.Contribution No. 1095, Department of Entomology, No. 1312 Department of Agronomy, Kansas Agricultural Experiment Station, Manhattan, Kansas 66506, USA. Present address: CIAT, Apdo, Aereo 6713, Cali, Colombia.     

Heavy metals (Cu,Zn, Cd,Pb) in sediment of the Java sea,estuarine and coastal areas of East Java and some deep-sea areas

The concentrations of copper, zinc, cadmium and lead were measured in the bulk sediment and the silt fraction of the surface sediment (upper 2 cm) from the riverine and estuarine zones of the rivers Brantas and Solo and in the adjacent coastal areas around East Java. The levels of contamination of the sediments with heavy metals were also determined in the Java Sea, some sites in the Bali Sea and the Indian Ocean.The concentrations of the trace elements were consistently higher in the silt fraction than in the bulk sediment. Trace element levels were higher in riverine and estuarine sediments than in sediment from coastal waters and the Java Sea. Increased copper, zinc and cadmium concentrations were measured in surface sediment from deep-sea areas.There were no or only minor differences in the metal concentrations in the sediment (both bulk sediment and the silt fraction) between the dry and the wet monsoon.     

Molecular markers assist in the development of diverse inbred backcross lines in European Long cucumber (<Emphasis Type="Italic">Cucumis sativus</Emphasis> L.)

The popular fresh-market European Long cucumber (Cucumis sativus L.) is grown commercially worldwide under controlled, greenhouse environments. However, it has a narrow genetic base, where private and public improvement programs can trace their origins to comparatively few accessions. Therefore, a project was designed to identify diverse genotypes for use in the formation and analysis of inbred backcross (BC₂S₃) lines (IBL) to broaden the genetic base of this market class. Initially, 42 cucumber accessions were evaluated with a previously defined standard marker array to identify parents for use in backcrossing. The IBL were developed by crossing the elite commercial line NZ1 (Nunhems Vegetable Seeds, Haelen, The Netherlands) and PI 432858 (China), and then backcrossing the most genetically diverse BC₁ and BC₂ progeny to the elite parent as defined by marker analyses (19 polymorphic, mapped SSR, and SCAR marker loci), followed by three generations of single seed descent resulting in 116 IBL (BC₂S₃). The IBL were evaluated under greenhouse conditions for days to anthesis, sex expression, lateral branch number, yield, and exterior fruit quality in Madison, Wisconsin, USA (soil media), and in Haelen and Bergschenhoek, The Netherlands (soilless, hydroponic media). The IBL were genotyped using an expanded marker array (37 polymorphic SSR, SCAR, SNP, EST, BAC end, and gene-associated loci), and genetic relationships were examined by multivariate analyses using phenotypic and genotypic data. The 116 developed IBL possessed considerable morphological and genotypic diversity, where genetic distance (GD) among lines ranged between 0.00 and 0.77. These IBL possessed many commercially acceptable attributes, and, thus, genetic diversity in this market type could be substantially increased by the use of these genetically broad-based IBL during plant improvement.     

Potential for Selection in the Progeny of an Interspecific Hybrid in Foxtail Millet

Genetic variation for morphology and grain yield components was studied in the F₂ and 14 F₃ families of an interspecific cross of Setaria italica (foxtail millet) with S. viridis s. s. (green foxtail). It appeared possible to recover the cultivated type using a simple selection procedure in F₂ and F₃. Comparison with a cross involving S. viridis var. major (giant green foxtail) is discussed.     

Selection in early generations and the occurrence of heterosis for the character root distribution

Crops of bean are sensible to climate changes, especially water stress. One way to minimize this instability is through genetic breeding of root system character. Thus, the objective of this study was to identify genotypes with superior root system in the first segregating generation at three depths in the soil profile and also verify the occurrence of heterosis for the root system character. Evaluations were performed using the method of Bohm (Methods studying root systems. Springer, Berlin 1979) at three different depths (0–10, 10–20 and 20–30 cm), in the experimental area of the Institute of Molecular Genetics and Breeding, at the State University of Santa Catarina UDESC Lages-SC. Twelve segregating populations and four parents (BAF 09, BAF 07, BAF 50 and IPR Uirapuru) were assessed by comparison. The favorable genotypes to the progress of generations are: two, seven and three for depths up to 20 cm and three for depths up to 30 cm. The cross between the parents BAF 07 (black group) and BAF 50 (carioca group) presented wide genetic divergence, providing significant increase in the root system revealed by the analysis of their progenies. The selection of superior genotypes in the layer of 20–30 cm was limited because most genotypes have similar and poorly distribution. Due to the strong effect of the dominance component, heterosis occurred for root distribution in early generation. This fact may interfere in the selection of autogamous species of bean related to this genetic character.     

西昌地区切花康乃馨保鲜剂配方的筛选

为了解决康乃馨采后运输和瓶插过程中花朵衰老、细胞膜破坏的问题,研究了不同配方保鲜剂对切花康乃馨品种马斯特(Master)瓶插期间的花枝鲜重、开花级数、花朵直径、CAT(过氧化氢酶)活性的影响。结果表明,C配方(3%Sug 300mg/l8-HQC 500mg/lGlg 20mg/l6-BA)的保鲜效果最好。