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Gene distributions and population genomics suggest artificial selection of ghd7 osprr37, for extremely early heading date of rice, in the Tohoku region of Japan. The ranges of cultivated crops expanded into various environmental conditions around the world after their domestication. Hokkaido, Japan, lies at the northern limit of cultivation of rice, which originated in the tropics. Novel genotypes for extremely early heading date in Hokkaido are controlled by loss-of-function of both Grain number, plant height and heading date 7 (Ghd7) and Oryza sativa Pseudo-Response Regulator 37 (OsPRR37). We traced genotypes for extremely early heading date and analyzed the phylogeny of rice varieties grown historically in Japan. The mutations in Ghd7 and OsPRR37 had distinct local distributions. Population genomics revealed that varieties collected from the Tohoku region of northern Japan formed three clusters. Mutant alleles of Ghd7 and OsPRR37 appear to have allowed rice cultivation to spread into Hokkaido. Our results show that the mutations of two genes might be occurred in the process of artificial selection during early rice cultivation in the Tohoku region.

While no significant differences in initial ovule number were found among oilseed rape genotypes, there was a large variation in effective ovule number (EON), which determines the final seeds per silique (SPS), a critical component of yield. In this study, we selected 18 oilseed rape genotypes with contrasting nitrogen utilization efficiency (NUtE) to unravel the main factors responsible for different EON and determine the critical period of EON formation under both a field and a pot experiments from 2016-2018. The high NUtE genotypes displayed significantly higher NUtE by 14.3%, along with greater yield per plant (29.4%) and SPS (21.1%) than the low NUtE genotypes. The greater productivity of the high NUtE genotypes was associated with 44.1% higher pollen grain number, 23.5% greater pollen viability, and 39.3% lower ovule abortion rate, compared to the low NUtE genotypes. In addition, the heart stage was the critical ovule development period for delineating the variability of EON among contrasting NUtE oilseed rape genotypes, when the high NUtE genotypes displayed higher silique net photosynthetic rate, surface area, biomass, and RNA expression levels. Taken together, this study indicated the pollen grain number, pollen viability and ovule abortion rate contributed to the final variation in EON and the heart stage was the critical period of determining the EON differences among contrasting NUtE genotypes. Increasing pollen grain number and pollen viability, and decreasing ovule abortion rate before heart stage should be the prerequisite for breeders to improve yield and NUtE of oilseed rape genotypes.

Grain weight and grain number, the two important yield traits, are mainly determined by grain size and panicle architecture in rice. Herein, we report the identification and functional analysis of OsSPL4 in panicle and grain development of rice. Using CRISPR/Cas9 system, two elite alleles of OsSPL4 were obtained, which exhibited an increasing number of grains per panicle and grain size, resulting in increase of rice yield. Cytological analysis showed that OsSPL4 could regulate spikelet development by promoting cell division. The results of RNA-seq and qRT-PCR validations also demonstrated that several MADS-box and cell-cycle genes were up-regulated in the mutation lines. Co-expression network revealed that many yield-related genes were involved in the regulation network of OsSPL4. In addition, OsSPL4 could be cleaved by the osa-miR156 in vivo, and the OsmiR156-OsSPL4 module might regulate the grain size in rice. Further analysis indicated that the large-grain allele of OsSPL4 in indica rice might introgress from aus varieties under artificial selection. Taken together, our findings suggested that OsSPL4 could be as a key regulator of grain size by acting on cell division control and provided a strategy for panicle architecture and grain size modification for yield improvement in rice.

The cultivation of sweet corn is expanding in Brazil, but there are serious constraints about the availability of commercial cultivars. The selection of superior sweet corn genotypes can be performed based on selection indexes based on plant agronomic characteristics. Thus, the objective of this work was to compare selection indexes to select sweet corn genotypes aiming greater productions. The experiment was conducted at the Vegetable Experimental Station of the Federal University of Uberlândia, Campus Monte Carmelo. Eighteen sweet corn accessions (F3 generation) were evaluated. The selection indexes applied to the agronomic characteristics of sweet corn were: direct and indirect, the sum of ranks, desired gains and ideotype indexes. The characteristics evaluated presented significant differences among genotypes, except for stem diameter, prolificacy and grain number per corncob. The coefficients of variation were below 30%, and the genetic parameters were satisfactory for most of the characteristics. The greatest gains with direct selection were in production (21.23%) and productivity of commercial sweet corn ear (15.19%), however, the indirect gains are unsatisfactory for sweet corn selection, and the sum of ranks index provided a balanced distribution of gains. The sweet corn genotypes L2P11, L2P37, P45, L2L5P3, and L5P18 presented a superior performance for the set of characters evaluated.

Background: In breeding programs, the selection of cultivars with the highest yield potential consisted in the selection of the yield per se, which resulted in cultivars with higher grains per spike (GN) and occasionally increased grain weight (GW) (main numerical components of the yield). In this study, quantitative trait loci (QTL) for GW, GN and spike fertility traits related to GN determination were mapped using two doubled haploid (DH) populations (Baguette Premium 11 × BioINTA 2002 and Baguette 19 × BioINTA 2002). Results: In total 305 QTL were identified for 14 traits, out of which 12 QTL were identified in more than three environments and explained more than 10% of the phenotypic variation in at least one environment. Eight hotspot regions were detected on chromosomes 1A, 2B, 3A, 5A, 5B, 7A and 7B in which at least two major and stable QTL sheared confidence intervals. QTL on two of these regions (R5A.1 and R5A.2) have previously been described, but the other six regions are novel. Conclusions: Based on the pleiotropic analysis within a robust physiological model we conclude that two hotspot genomic regions (R5A.1 and R5A.2) together with the QGW.perg-6B are of high relevance to be used in marker assisted selection in order to improve the spike yield potential. All the QTL identified for the spike related traits are the first step to search for their candidate genes, which will allow their better manipulation in the future. EEA Marcos Juárez Fil: Pretini, Nicole. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentina Fil: Pretini, Nicole. Universidad Nacional del Noroeste de la Provincia de Buenos Aires (UNNOBA). Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentina. Fil: Vanzetti, Leonardo Sebastian. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; Argentina Fil: Vanzetti, Leonardo Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Terrile, Ignacio Ismael. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Departamento de Trigo; Argentina Fil: Donaire, Guillermo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juarez; Argentina. Fil: González, Fernanda Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentina. Fil: González, Fernanda Gabriela. Universidad Nacional del Noroeste de la Provincia de Buenos Aires (UNNOBA). Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentina Fil: González, Fernanda Gabriela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; Argentina.

Crop yield is determined by the acquisition and allocation of photoassimilates in sink organs. Therefore, genetic modification of sink size is essential for understanding the complex signaling network regulating sink strength and source activities. Sink size in wheat depends on the number of spikelets per spike, floret/grain number per spikelet as well as the grain weight or dry matter accumulation. Hence, increasing spikelet number and improving sink size are targets for wheat breeding. The main objective of the present work was to genetically modify the wheat spike architecture, i.e., the sink size by introgressing the ‘Miracle wheat’ or the bht-A1 allele into an elite durum wheat cv. Floradur. After four generations of backcrossing to the recurrent parent, Floradur (FL), we have successfully developed Near Isogenic Lines (NILs) with a modified spikelet arrangement thereby increasing spikelet and grain number per spike. Genotyping of bht-A1 NILs using the Genotyping-By-Sequencing approach revealed that the size of the introgressed donor segments carrying bht-A1 ranged from 2.3 to 38 cM. The size of the shortest donor segment introgressed into bht-A1 NILs was estimated to be 9.8 mega base pairs (Mbp). Phenotypic analysis showed that FL-bht-A1-NILs (BC3F2 and BC3F3) carry up to seven additional spikelets per spike, leading to up to 29% increase in spike dry weight at harvest (SDWh). The increased SDWh was accompanied by up to 23% more grains per spike. More interestingly, thousand kernel weight (TKW) did not show significant differences between FL-bht-A1-NILs and Floradur, suggesting that besides increasing spikelet number, bht-A1 could also be targeted for increasing grain yield in wheat. Our study suggests that the genetic modification of spikelet number in wheat can be an entry point for improving grain yield, most interestingly and also unexpectedly without the trade-off effects on TKW. Hence, FL-bht-A1-NILs are not only essential for increasing grain number, but also for understanding the molecular and genetic mechanism of the source–sink interaction for a clearer picture of the complex signaling network regulating sink strength and source activities.

In order to characterize the response to drought of 19 ethyl methanesulfonate (EMS)-mutagenized lines of durum wheat (Triticum durum Desf.) derived from the variety CHAM-1 and cultivated in Morocco, growth (plant height, PLH) and yield (grain number per spike, GNS) parameters were followed for different lines and CHAM-1 variety. All were cultivated under well-watered (C) and drought conditions (T). In parallel, quantitative and qualitative aspects of leaf peroxidases (EC 1.11.1.7) were analyzed. When compared with C plant lines, the corresponding T lines showed decreases of 9–38% and 1–78%, respectively, for PLH and GNS parameters. A positive correlation was found between PLH and the yield as GNS (r2 = 0.885). When expressed as units mg−1 proteins, soluble peroxidases (SPOX) were less represented than the ionically wall-bound peroxidases (IPOX) in all mutagenized wheat lines, with 22.1% and 46.2% as respective coefficients of variation for drought-stressed lines. Drought-induced reduction in grain yields for all lines correlated positively with percentages of IPOX exhibited by stressed plants (r2 = 0.68). In addition, Averages of drought-induced decreases in GNS, calculated for five groups of mutagenized lines, were found to be positively correlated with their respective percentages of IPOX (r2 = 0.906). Drought-adapted lines showed decreases in IPOX. When subjected to electrophoresis using 6–15% polyacrylamide gradient gels, resolved IPOX of cereal line groups of limited drought-induced reduction in GNS exhibited low reactivity on native gels. These data support the hypothesis that IPOX are indicators of the sensitivity of wheat lines to drought conditions. Possible mechanisms of POX involvement in wheat resistance to drought and developing appropriate biochemical tests to screen variability and drought adaptation of EMS mutants are discussed in this study.

Key message A novel TaGW2-A1 allele was identified from a stable, robust QTL region, which is pleiotropic for thousand grain weight, grain number per spike, and grain morphometric parameters in wheat. Abstract Thousand grain weight (TGW) and grain number per spike (GNS) are two crucial determinants of wheat spike yield, and genetic dissection of their relationships can help to fine-tune these two components and maximize grain yield. By evaluating 191 recombinant inbred lines in 11 field trials, we identified five genomic regions on chromosomes 1B, 3A, 3B, 5B, or 7A that solely influenced either TGW or GNS, and a further region on chromosome 6A that concurrently affected TGW and GNS. The QTL of interest on chromosome 6A, which was flanked by wsnp_BE490604A_Ta_2_1 and wsnp_RFL_Contig1340_448996 and designated as QTgw/Gns.cau-6A, was finely mapped to a genetic interval shorter than 0.538 cM using near isogenic lines (NILs). The elite NILs of QTgw/Gns.cau-6A increased TGW by 8.33%, but decreased GNS by 3.05% in six field trials. Grain Weight 2 (TaGW2-A1), a well-characterized gene that negatively regulates TGW and grain width in wheat, was located within the finely mapped interval of QTgw/Gns.cau-6A. A novel and rare TaGW2-A1 allele with a 114-bp deletion in the 5′ flanking region was identified in the parent with higher TGW, and it reduced TaGW2-A1 promoter activity and expression. In conclusion, these results expand our knowledge of the genetic and molecular basis of TGW-GNS trade-offs in wheat. The QTLs and the novel TaGW2-A1 allele are likely useful for the development of cultivars with higher TGW and/or higher GNS. Electronic supplementary material The online version of this article (10.1007/s00122-017-3017-y) contains supplementary material, which is available to authorized users.

Identification of secondary traits in mapping populations is usually hindered by the strong effect of anthesis time. Thus, considering the variability in time to anthesis in combination with an accurate phenotyping of mapping populations and available molecular tools is a possible way for recognising secondary traits to improve yield potential. The aim of this work was to identify secondary traits to perform indirect selection for grain yield (GY) in a bread wheat mapping population consisting of 124 doubled haploid lines, derived from the cross between two soft red winter wheat genotypes with contrasting photoperiod response. Genomic regions linked to different traits were analysed under two environments. The population showed a strong effect of time to anthesis over GY, as expected. A large variability in GY was observed but only two QTLs were detected on chromosome 5A for this trait, which co-localized with QTLs of time to anthesis. GY variation was partially associated with above-ground dry matter at maturity (AGDM) and to a lesser extent with harvest index (HI). Detected QTLs for grains per m2 (GN), grain weight, AGDM and HI explained between 25 and 61% of the GY additive genetic variance. GN, defined as the product between spike dry weight at anthesis (SDW) and fruiting efficiency (FE), was the main numerical component that explained most of the variation in GY. Five QTLs were detected for SDW, which did not co-localize with QTLs of time to anthesis and captured ca. 50% of the additive genetic variance, while there was a weak relationship between NG and FE. When genotypes were filtered by similar anthesis time and plant height, SDW was identified as a promising secondary trait to be targeted for indirect selection of GY.

Background Leaf morphology and spikelet number are two important traits associated with grain yield. To understand how genes coordinating with sink and sources of cereal crops is important for grain yield improvement guidance. Although many researches focus on leaf morphology or grain number in rice, the regulating molecular mechanisms are still unclear. Results In this study, we identified a prohibitin complex 2α subunit, NAL8, that contributes to multiple developmental process and is required for normal leaf width and spikelet number at the reproductive stage in rice. These results were consistent with the ubiquitous expression pattern of NAL8 gene. We used genetic complementation, CRISPR/Cas9 gene editing system, RNAi gene silenced system and overexpressing system to generate transgenic plants for confirming the fuctions of NAL8. Mutation of NAL8 causes a reduction in the number of plastoglobules and shrunken thylakoids in chloroplasts, resulting in reduced cell division. In addition, the auxin levels in nal8 mutants are higher than in TQ, while the cytokinin levels are lower than in TQ. Moreover, RNA-sequencing and proteomics analysis shows that NAL8 is involved in multiple hormone signaling pathways as well as photosynthesis in chloroplasts and respiration in mitochondria. Conclusions Our findings provide new insights into the way that NAL8 functions as a molecular chaperone in regulating plant leaf morphology and spikelet number through its effects on mitochondria and chloroplasts associated with cell division.

Moderate overexpression of CYP734A4 improves grain number per main panicle and seed setting rate. Brassinosteroid (BR) homeostasis and signaling are crucial for plant growth and development. CYP734A genes encode cytochrome P450 monooxygenases that control the level of bioactive BRs by degrading BRs. However, fertile plants overexpressing CYP734As have not been reported in rice. Here, we isolated a novel semi-dominant mutant brd3-D, in which T-DNA was inserted approximately 4 kb upstream of the CYP734A4 gene (GenBank Accession AB488667), causing its overexpression. The mutant is characterized by dwarfism, small grains, and erect leaves and is less sensitive to brassinolide-induced lamina joint inclination and primary root elongation. However, increased grain number per main panicle and improved seed setting rate were also found in heterozygous brd3-D. To our knowledge, these traits have not been reported in other BR deficient mutants. Quantitative real-time PCR analysis indicated that phenotypic severity of the brd3-D mutant is positively correlated with the CYP734A4 transcription level. In accordance with the increased expression of CYP734A4, a lower castasterone (a rice BR) content was detected in the brd3-D mutants. Knockout of brd3-D by using the CRISPR/Cas9 system rescued the mutation. In addition, transgenic plants overexpressing CYP734A4 with the 35S enhancer mimicked the brd3-D phenotypes, confirming that moderate overexpression of the CYP734A4 gene can improve grain number per main panicle and the seed setting rate in rice. Further studies showed that overexpression of CYP734A4 influences the expressions of multiple genes involved in the BR pathway, and the expression of CYP734A4 is induced by exogenous brassinolide, confirming the negative regulatory role of CYP734A4 in the BR pathway. CYP734A4 might provide a useful gene resource for developing new high-yielding rice varieties.

Background Despite the great contributions of utilizing heterosis to crop productivity worldwide, the molecular mechanism of heterosis remains largely unexplored. Thus, the present research is focused on the grain number heterosis of a widely used late-cropping indica super hybrid rice combination in China using a high-throughput next-generation RNA-seq strategy. Results Here, we obtained 872 million clean reads, and at least one read could maps 27,917 transcripts out of 35,679 annotations. Transcript differential expression analysis revealed a total of 5910 differentially expressed genes (DGHP) between super-hybrid rice Wufengyou T025 (WFYT025) and its parents were identified in the young panicles. Out of the 5910 DGHP, 63.1% had a genetic action mode of over-dominance, 17.3% had a complete-dominance action, 15.6% had a partial-dominance action and 4.0% had an additive action. DGHP were significantly enriched in carotenoid biosynthesis, diterpenoid biosynthesis and plant hormone signal transduction pathways, with the key genes involved in the three pathways being up-regulated in the hybrid. By comparing the DGHP enriched in the KEGG pathway with QTLs associated with grain number, several DGHP were located on the same chromosomal segment with some of these grain number QTLs. Conclusion Through young panicle development transcriptome analysis, we conclude that the over-dominant effect is probably the major contributor to the grain number heterosis of WFYT025. The DGHP sharing the same location with grain number QTLs could be considered a candidate gene and provide valuable targets for the cloning and functional analysis of these grain number QTLs. Electronic supplementary material The online version of this article (10.1186/s12284-018-0229-y) contains supplementary material, which is available to authorized users.

Generally, lead-free solder joints in electronic device are near single or multi crystalline rather than poly crystalline, and the fatigue failure behavior of solder joints is greatly influenced by the solder joint thickness. In this study, the grain number and orientation of solder joints with four solder thicknesses (0.1, 0.2, 0.3, 0.6 mm) were analyzed and the effect of that on the low cycle fatigue deformation behavior of solder joint was also investigated. The orientation analysis was conducted by means of electron backscatter diffraction and the fatigue test was performed under room temperature with a fixed frequency of 1 Hz. Moreover, the deformation evolution on side surface of solder joint was observed by utilizing scanning electron microscope. It is shown that there is no preferred solidification orientation for lead-free solder joints. However, grains in one joint seem to have a similar orientation when the solder thickness is

Background Rice plays an extremely important role in food safety because it feeds more than half of the world’s population. Rice grain yield depends on biomass and the harvest index. An important strategy to break through the rice grain yield ceiling is to increase the biological yield. Therefore, genes associated with organ size are important targets for rice breeding. Results We characterized a rice mutant gns4 (grain number and size on chromosome 4) with reduced organ size, fewer grains per panicle, and smaller grains compared with those of WT. Map-based cloning indicated that the GNS4 gene, encoding a cytochrome P450 protein, is a novel allele of DWARF11 (D11). A single nucleotide polymorphism (deletion) in the promoter region of GNS4 reduced its expression level in the mutant, leading to reduced grain number and smaller grains. Morphological and cellular analyses suggested that GNS4 positively regulates grain size by promoting cell elongation. Overexpression of GNS4 significantly increased organ size, 1000-grain weight, and panicle size, and subsequently enhanced grain yields in both the Nipponbare and Wuyunjing7 (a high-yielding cultivar) backgrounds. These results suggest that GNS4 is key target gene with possible applications in rice yield breeding. Conclusion GNS4 was identified as a positive regulator of grain number and grain size in rice. Increasing the expression level of this gene in a high-yielding rice variety enhanced grain yield. GNS4 can be targeted in breeding programs to increase yields. Electronic supplementary material The online version of this article (doi:10.1186/s12284-017-0171-4) contains supplementary material, which is available to authorized users.

Studies on plant development phases and yield component patterns of wheat are essential for a better understanding of adaptation in wheat. Our main aim was to carry out detailed phenological analyses of 18 wheat genotypes in three sowing times for determining the effect of sowing date on individual phenophases, and yield components. Sowing date had the single greatest effect on the start of intensive stem elongation. The longer vegetation period had a favourable effect on main spike length and on the spikelet number per spike, but had no influence on thousand-kernel weight and grain number per spike. The time between the first node appearance and start of intensive stem elongation had a significant effect on the number of reproductive tillers. A close association (R2 = 0.191) was observed during the second phase of intensive stem elongation between the boot stage-to-heading interval and the number of spikelets per spike. Two-way analysis of variance on the yield components showed that the sowing date, as a main factor, had a weaker effect on the phenophases than on morphological and developmental parameters. The insensitive allele of the Ppd-D1 gene shortened the time required for first node appearance and heading both in autumn and spring sowing.

The 0.50-mm-thick Fe81Ga19 sheets were produced by rolling procedure, and texture evolution was investigated using macro- and microtexture analyses. The recrystallization texture dominated with strong η fiber (〈001〉//RD) was successfully obtained through sheet thickness by primary recrystallization annealing. The η fiber development can be attributed to the advantage in both grain number and grain size derived from the specially applied rolling process.

Total spikelet number per panicle (TSN) is thought to be one of the most important agronomic traits associated with grain production in rice (Oryza sativa L.). We previously reported the development of 334 introgression lines (ILs) with variations in agronomic traits in the genetic background of indica rice variety IR64. Among these, an IL derived from high-yielding rice variety Hoshiaoba showed significantly higher TSN than IR64. We therefore have conducted a quantitative trait locus (QTL) analysis for TSN in an F2 population of IL × IR64 to ascertain the genetic basis for the high TSN of the IL. The analysis revealed the presence of a QTL for TSN on chromosome 7, where several QTLs for grain number have been previously reported. We developed a near-isogenic line (NIL) for this QTL by using DNA marker-assisted selection and characterized its effect. The NIL showed significantly higher TSN than IR64. These results suggest that the QTL and the NIL will be useful materials in breeding programs aimed at increasing TSN.

The parents (the landrace Chinese spring (CS) and a synthetic hexaploids (S6x)) and 17 derived single chromosome substitution lines (SL) were grown in parallel in the field under non-saline (1.0 dSm−1) and saline (12.0 dSm−1) conditions, and evaluated for a set of phenotypic traits. The performance of CS indicated it to have borderline salinity tolerance with respect to all of the traits except for leaf area (for which it behaved in as a salinity sensitive type). The SL 4D was early in booting, ear emergence, flowering and maturity, while 5D and 2B SLs were both late. The 2B SL produce 33% more ears than CS. The 5D SL under-performed with respect to ear weight, grain number per ear, grain weight per ear and 1000-grain weight both under non-saline and saline conditions. Under saline conditions, four SLs (1A>5A>1D>2B) outperformed Cs for ear length, and six SLs (1D>6A>4B>3A>3B>3D) showed an improved grain weight. The grains produce by the 2B SL were smaller than those of CS. Leaf area developed better in four SLs (4D>2B>1A>7D) than in CS.

Spiral grain selectors are used to grow single-crystal (SX) turbine blades during investment casting. Competitive growth in the spiral selectors leads to the selection of a single grain that subsequently grows to form the blade. In this study, the effect of spiral design on grain selection during investment casting was investigated through a series of experiments. It is found that the spiral design can effectively reduce the grain number but is not able to optimize axial grain orientations during solidification, the effectiveness of grain selection is strongly dependent on the spiral “take-off” angle, and spirals with smaller take-off angles are most potent. It is proposed that grain selection in the spiral is controlled by the geometry of the spiral via a “geometrical blocking” mechanism.

We used a water-centred framework (yield = transpiration × transpiration efficiency × harvest index) to investigate the effect of soil salinity on growth and yield of wheat and barley. Our working hypothesis is that salinity reduces transpiration proportionally more than transpiration efficiency. We established a glasshouse experiment with the factorial combination of four varieties (wheat: Janz, Krichauff; barley: Mundah, Keel) and three soil treatments: a control with no NaCl added, and NaCl added to achieve soil EC1:5 0.75 dS m−1 and 1.5 dS m−1. Pot-grown plants were watered to weight to determine transpiration and shoot dry matter was determined using a non-destructive image analysis system. Consistent with our hypothesis, salinity reduced transpiration (30–60%) proportionally more than transpiration efficiency (0–35%); transpiration accounted for 90% of the variation in shoot growth across varieties and treatments. Against this pattern, there were time- and variety-dependent responses. The rate of leaf appearance and the transpiration efficiency of Janz, Krichauff and Keel showed a two-stage response to salinity. In stage 1, salt-stressed plants maintained rate of leaf appearance and transpiration efficiency close to or slightly below those of the controls. After a clear break point where the slope changed, stage 2 was characterised by a substantial reduction in both traits. Stage 2 was not evident in salt-stressed Mundah, which maintained a relatively high rate of leaf appearance and transpiration efficiency. Across species, harvest index increased from 0.40 in controls to 0.47 at 0.75 dS m−1. Harvest index of plants grown at 1.5 dS m−1 was unaffected in wheat, and was reduced in barley. We propose that an understanding of the effect of salinity on crop development, growth and yield requires integration of low-level traits in a framework of resource capture, resource-use efficiency and plant allocation. Osmotic stress tolerance, Na+ exclusion, and tissue tolerance to accumulated Na+ would improve yield of salt-stressed crops to the extent that these traits contribute to the maintenance of water uptake and harvest index. Refereed/Peer-reviewed

Using cultivating experiments in fields under drought stress, yields and characteristics in morphology, growth and development of different genotype maize inbred lines were studied systematically. We evaluated and classified the drought resistance of these materials based on the needed indexes, including subordinate function values of drought resistance (SV), drought coefficient (DC) and drought index (DI) of yield by fuzzy function method and cluster analysis. We also analyzed the correlations between parameters and tested values of traits. The effective parameters and indexes of comprehensive evaluation for drought resistance were selected with principal component analysis. The results showed that under drought stress, the yield of maize inbred lines obviously decreased. The anthesis and silking interval (ASI) was prolonged compared with the control, with a smaller leaf area, thinner stalk, shorter and smaller ears, lengthened barren ear tip, a decline in plant height and ear position, reduced grain number per ear and grain weight, which led to a yield decline. Effects of drought treatment on different maize inbred lines were significantly different. 79-1E, Jiao51, Su1-1 and 18599 were found to be highly resistant to drought, while 1125 and 5311 performed the worst. DI and SV were significantly correlated with drought resistance. Our results indicated that DI, SV, yield and leaf area could be used as parameters and indexes to effectively evaluate the drought resistance of maize. Meanwhile, DC, plant height, ASI, grain number per ear or row, ear length and diameter could be taken as auxiliary parameters and indexes. An applied scientific method for the comprehensive evaluation of drought resistance was offered in this paper.

Two recombinant inbred lines (RILs) populations, RILSA derived from the cross between “Zhongyouzao8” (indica) and “Toyonihiki” (japonica) rice cultivars, and RILSB derived from the cross between “Qishanzhan” (indica) and “Akihikari” (japonica) rice cultivars, were grown in Liaoning and Sichuan Provinces, China to understand the effects of ecological environments on the subspecies characteristics and economic traits in filial generations of cross between indica and japonica. The results showed that both the subspecies characteristics and economic traits changed significantly. The effects of ecological environments on Cheng’s index and six subspecies characteristics were different on the basis of populations or characteristics. The distribution of Cheng’s index in RILSA was japonicalinous in Liaoning and Sichuan. The distribution of Cheng’s index in RILSB approached to normal distribution in Liaoning, but it was japonicalinous in Sichuan. As a whole, the two populations were more japonicalious in Sichuan than in Liaoning. The panicle number, seed setting rate and per-thousand-grain weight were decreased significantly in Sichuan. The grain number per panicle showed no significant change. A significant positive correlation was found between Cheng’s index and the economic traits, including six subspecies traits. It suggested that the reason that the filial generation of cross between indica and japonica in northern China showed japonicanous subspecies characteristics might be the artificial selection by breeders on the economic traits. In addition, indica-japonica differentiation and the relationship with ecological environments were discussed.

Changes in the yield components of 35 barley varieties, which formed eight adaptation groups, were studied as a function of daylength and vernalization treatment under controlled conditions. Changes in the daylength had a significant effect on the yield components in the majority of adaptation groups, though the extent and direction of these changes varied. In spring barley groups there was an increase in plant height, number of reproductive tillers and in the thousand kernel weight, while the number of spikelets, the grain number of the main spike and the grain yield decreased as the daylength became shorter. Among the winter barley varieties, changes in daylength had a significant influence on yield components only in those groups, which were sensitive to long and/or short days. The groups sensitive to long days produced higher grain yields under long-day conditions than the insensitive group. Under short days the grain yield of groups sensitive to short days declined to a greater extent than that of the insensitive group. The effect of vernalization on the yield components depended strongly on the vernalization requirements of winter barleys. Most of the yield components of winter barleys with the highest vernalization responses were significantly influenced, with the exception of the grain number in the main spike. Changes in yield components showed specific patterns between these eight groups well corresponding to the different adaptation types determined by their heading date characteristics.

Modulating the expression of two flowering-genes can be used to produce wheat spikes with modified spikelet arrangement and higher grain number.

During the process of plant breeding and selection of new winter wheat cultivars a lot of attention is paid to the improvement of the main components of grain yield-number of ears/m2, number of grains per ear and 1000 seed weight. Production of cultivars that achieve a large number of fertile ears per unit area, a large number of grains per ear and a heavy 1000 seed weight, even with a lower density, would mean that a high grain yield is achieved with lower costs. It is of great importance for wheat production in Croatia. Along with the research on sowing rate influence (400, 500, 600 and 700 germinable seeds/m2) on winter wheat grain yield, other trials were done on the grain yield components (number of ears per unit area, number of grains per ear and 1000 seed weight) during periods 1996–1997 and 1997–1998 both on three AG cultivars of winter wheat Lara, Kruna and Lenta and on the check cultivar Ẑitarka. The trial was done according to the split-plot method in 4 replications. Statistically speaking, various sowing rates had a very significant influence on the number of ears per unit area. The largest number was achieved with the sowing rate of 700 germinable seeds/m2 (783,38 ears/m2). This number of ears is statistically more significant (P

Douglas fir trees, Pseudotsuga menziesii, vary greatly in their self-fertility, but little is known about the relationship of self-fertility to outcrossing success. If low self-fertility pollen donors have lethal recessive alleles that are widespread, then in crosses with other trees they should have poor paternal success competing with high self-fertility donors that have few recessive lethals. We compared Douglas fir trees with high and low self-fertility for differences in pollen grain size, pollen number per milligram, and respiration rate. Pair-wise mixtures of pollen from individuals with high and low self-fertility were applied in controlled pollinations. Electrophoretic markers identified seed paternity. The pollen donors did differ in all three pollen traits but, as a class, the low self-fertility donors had neither inferior pollen nor low paternal success in outcrossing. Paternal success depended upon the identity of the competing pollen donors and the seed parent. It was not related to pollen grain number or respiration rate, but donors with the smaller pollen grains in a mixture had greater success.

Distribution and accumulation of dry matter (d.m.) and nitrogen (N) were investigated within ears of a semidwarf, a gigas, and a normal wheat genotype grown under controlled environments. A high harvest index was linked with a small pre-anthesis N-storage (and vice versa) but this did not affect N amounts in grains because of compensation by prolonged N uptake during grain filling. N distribution within and between spikelets roughly paralleled that of d.m. Nevertheless, the two processes appeared to be rather independent as became evident from comparisons of the time courses in and between the genotypes. Final distribution of d.m. and N within and between spikelets mainly depended on different rates during the linear phases of accumulation and less on the duration. Maximum of d.m. and N weights per grain as well as maximum of grain number were observed in spikelets below the middle of the ear axis. This ‘submedian dominance’ suggested a pre-anthesis determination of the accumulation potential of grains in different spikelets. N percentage within spikelets disclosed that N accumulation was hampered more than that of d.m. in those positions unfavourable to the latter process. This principal pattern was not affected by genotypes in spite of considerable differences in numbers and weights of grains.

Field trials were conducted at Samaru over a three-year period (1980–82) to study the yield, growth and nutrient concentration of three grain sorghum varieties (L. 187, SK5912 and FFBL) in relation to potassium fertilization in a savanna soil. Potassium application rates were 0, 25, 50 and 75 kg K ha−1. Year × potassium interactions were not significant although there were significant variety × K interactions. The highest grain yields for var. L.187, SK5912 and FFBL occurred from the application of 25, 50 and 75 kg K ha−1 respectively. Straw yield was generally increased by K application, which also promoted tillering and hastened flowering in grain sorghum. Although grain weight per head, head number per m2, grain number and 1000-grain weight were unaffected by this nutrient, weight per head was reduced by 22.8 per cent. K application enhanced N concentration of sorghum plants but caused decline in P concentration. The highest K rate gave the highest K concentration in each of the three varieties at 7 weeks after planting. Optimum K requirement of grain sorghum would seem to be between 25 and 50 kg K ha−1.

Deparaffinized and Feulgen-stained sagittal sections of the mouse brain were studied interferometrically in order to measure optical path differences of euchromatin and heterochromatin of various cell types. Furthermore, the ratio eu-: heterochromatin of each cell type was determined. From these data mass densities of karyoplasm and, finally, correction factors of 3H-beta-self-absorption were calculated for comparing grain numbers of different cell types in quantitative autoradiographic studies after application of tritium-labelled substances. Remarkable differences of correction factors up to a factor of 2.18 were found. Furthermore, the actual section thickness was determined interferometrically. A reduction to about 0.60 of the microtome setting was measured in two different areas of the brain. Using mass densities together with actual section thickness correction factors for a thickness of 1 micron were calculated. This was done also for cell types outside the brain the data of which were taken from literature. Thus, differences in correction factors up to about a factor of 4 were found pointing out the importance of considering 3H-beta-self-absorption in quantitative autoradiographic studies.

Studies on growth and grain yield of rice var:Jaya as influenced by graded levels of N and time of N application under continuous shallow submergence and/or cyclic submergence, have shown that the growth and dry matter production after flowering and consequently the grain yield of rice was significantly more under continuous shallow submergence than under cyclic submergence. The optimum dose of N for rice var:Jaya under conditions of these experiments was around 140 kg/ha. Panicle production and grain number per panicle increased significantly upto 150 kg N/ha, while there was a decline in panicle weight beyond 100 kg N/ha. Excessive N application beyond 150 kg/ha also resulted in more of spikelet sterility. The results indicate that under cyclic submergence, a minimum of three split applications of N are necessary, although the effect of two or three split applications were at par, under continuous shallow submergence.

The reciprocal monosomic analysis (RMA) technique of intervarietal chromosome manipulation was used to investigate the genetic control of grain weight in two varieties of wheat (Spica and Chinese Spring). The method enabled major genetic differences between the two varieties for this quantitative character to be assigned to individual chromosomes. The RMA was extended by the extraction of reciprocal disomic F3 families, of which individual ears were analysed at maturity for grain weight at each position within the ear. Chromosomes 1A, 1D and 7A of the large-grained parent, Spica, increased grain weight relative to the homologous chromosomes of the small-grained parent, Chinese Spring. The effect of chromosomes 1D and 7A were proportionately similar throughout the ear, while that of 1A was disproportionately greater in the distal florets of each spikelet. None of these differences involved simultaneous effects on grain number and thus could be considered to be specific genetic effects on grain growth.

The photometry of coronal colour negatives is carried out. The films were obtained at the March 7, 1970 and July 10, 1972 eclipses. A distribution of the coronal brightness in the red (635 nm), green (545 nm), and blue (455 nm) wavelength intervals up to distances of (6–7)R ⊙ is deduced (Figure 1). Colour indexes of the corona (the emission ratio red/blue - C rb and green/blue - C gb) have been obtained. We assume C rb = C gb = 1 in the inner corona (≤2R ⊙). The maximum of colour indexes of the 1970 corona are at the distances of about 4R ⊙ (C rb≤ 1.9 and C gb ≤ 1.7). A slight reddening within the limits of the errors was found in the 1972 corona. There is a correlation between colour indexes and diffuse external reinforcements (RED) brightness. The analysis of the results leads to the conclusion that RED consists of dust grains with radii ≥1 μm. RED brightness is evaluated to be 4 × 10-10 B ⊙. There is 1 grain of dust in the elementary volume with cross section of 1 cm2 along the line of sight. The intensity of dust emission in wavelength interval 10 μm deduced by the authors is approximately 1 μW cm-2 s m−1. That is in agreement with Mankin et al. (1974) and Lena et al. (1974) observations. The whole dust mass of RED is ≤1% of the coronal gas mass contained within RED region. The dust grain number density is about 10-11 cm-3. Determinations of the colour of the solar corona have been made by a number of scientists (Tikhov, 1940, 1957; Allen, 1946; Blackwell, 1952; Michard, 1956; Sharonov, 1958; Nay et al., 1961). The corona colour was found to be somewhat redder than the Sun's. However this question is not finally settled to date.

The inheritance of supernumerary spikelets was found to be controlled by two recessive genes with evidence for the possibility of a repressor(s) in crosses between normal and supernumerary spikelet wheats. In experimental lines with phenotypically normal heads but possessing the recessive supernumerary spikelet gene(s), increases in the number of nodes on the rachis (and hence the number of normal spikelets) fertility and grain number per head were found, as well as in the ‘normal’ Australian and American wheat cultivar Phoenix. This attribute has previously been suggested to be a way of increasing spikelet number in future wheat breeding.

Studies on the nature of relationship between grain size (in terms of thousand grain weight), grain number, rate of filling and yield have been worked out with late duration (140–150 days) rice varieties. Grain number per m2, grains per panicle and yield showed a negative relationship with grain size. There was no compensatory balance between grain size and grain number within a range of thousand grain weight of 15 to 30 g. Based on the peaks in grain filling activity, the varieties were classified into four groups. There was no relationship between grain size and rate of grain filling thereby suggesting that grain filling is determined by inherent endogenous factors.

The effect of frequency-dependent advantage in wheat was investigated by growing F1. hybrid seeds of the crosses (Warimek X Halberd) and (Wariquam x Halberd) in a stand of Halberd at 5 frequencies: 4 %, 6.25 %, 11.11 %, 25 % and 50 %. A reduction of 35 % to 40 % in grain yield of individual plants was observed with both hybrids as their frequencies changed from 4% to 50 %. A similar trend with frequency was noted for several other plant characteristics, including total grain number, particularly with those measured towards the end of the growing season. Halberd plants did not show a corresponding increase as their frequency declined from 96 % to 50%. - The following season, 76 F4 lines from the cross (Warimek X Halberd) and 70 F4 lines from (Wariquam x Gabo) were grown at frequencies of 6.25% and 18.75% in machine sown stands of Wariquam and Halberd, respectively. Again grain yield decreased as genotypic frequency increased. Furthermore, there was a positive correlation between frequency-dependent advantage and relative grain yield, suggesting that high yielding genotypes show a greater advantage at low frequencies than lower yielding ones.

Yield components and yield were studied in F1 barley hybrids produced by hand pollination or male sterility. Grain number exhibited only partial dominance but grain weight showed dominance or overdominance and contributed to the heterotic situation particularly in 2×6-row crosses. For the commercial exploitation of heterosis it is essential that hybrids should be found which show greater dominance for high grain number.