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1.
Summary Eight controlled crosses were made between seven different sweet-kerneled almond cultivars (Prunus dulcis [Mill.] D. A. Webb), and five crosses were made between sweet x highly floriferous bitter almond clones. Sweet x bitter progenies out-yielded the sweet x sweet matings by more than three to one in the first year of production. This was attributable to greater cropping efficiency rather than to tree size or precocity. There was no pleiotropic association or association due to linkage between bitterness and yield. The selected Alnem (bitter) clones appear to be potentially useful progenitors for increasing almond yield capacity by conventional breeding methodology. 相似文献
2.
Camila Cané-Retamales Freddy Mora Felipe Vargas-Reeve Sandra Perret Rodrigo Contreras-Soto 《Euphytica》2011,178(2):177-183
In the dry regions of Chile, prolific flowering from forest plantation is particularly advantageous for honey production,
in order to supplement the erratic flowering in native plants. Eucalyptus cladocalyx is a species suitable for areas with low water availability and their flowers provide a reliable source for the production
of honey. The aim of this study was to examine the heritability of flowering intensity in 49 open-pollinated families of E. cladocalyx in southern Atacama Desert, Chile, with the view to the selection for prolific flowering, but with minimal impact on precocious
flowering. The Bayesian variance component estimation model was assumed using the Gibbs sampling algorithm. Threshold models
were fitted to flowering data (bi-character model). Flowering intensity was found to be highly heritable (posterior mean:
h
2 = 0.48; and credible interval: 0.41–0.56). The posterior mean of the genetic correlation between flowering precocity and
intensity was positive (r = 0.45) and according to the credible interval (0.341–0.542), it was significantly different from zero, indicating that selection
on breeding values of early flowering at age three, would have significant and positive impact on flowering intensity 5 years
later (or in 8-year-old trees). These results are important for the start of a small-scale breeding program for the species
in southern Atacama Desert. The genetic variability found in these breeding populations may be used for breeding purposes
in regions where arid environmental conditions are limiting to the establishment of eucalypts trees. 相似文献
3.
Vanessa Prigge Raman Babu Biswanath Das M. Hernández Rodriguez Gary N. Atlin Albrecht E. Melchinger 《Euphytica》2012,185(3):453-463
Single crosses (SC) of elite inbreds and open-pollinated populations (OP) are suitable source germplasm for doubled haploid
(DH) line development in hybrid maize breeding, given that they combine a high population mean ([`(x)] \overline{x} ) for testcross performance with adequate response to selection (
\Updelta G \Updelta G ). This is the first study reporting testcross grain yield (TCGY) and dry matter content (TCDMC) evaluations of 131 DH lines
developed from ten tropical source germplasm comprising five OP (OP1–OP5) and five SC (SC1–SC5). Gene diversity (d) and the average number of alleles (a
r
) per locus was estimated for DH lines based on 24 simple sequence repeat markers. Analysis across three environments revealed
no significant differences between [`(x)] \overline{x} of OP- and SC-derived DH lines for TCGY and TCDMC. Significant genetic variance for both traits was only detected among OP-derived
DH lines which may be explained by a larger number of segregating quantitative trait loci (QTL) as suggested by higher d and a
r
values than in SC-derived DH lines. The usefulness criterion (
U = [`(x)] + \Updelta G U = \overline{x} + \Updelta G ) was higher for OP-derived DH lines for TCDMC, but higher for SC-derived DH lines for TCGY. DH lines from OP1, OP2, and OP3
showed high TCGY, suggesting that they may be useful in tropical hybrid breeding. We conclude that tropical OP represent a
valuable source of untapped genetic variation that can efficiently be exploited with DH technology for hybrid maize breeding. 相似文献
4.
H. T. Wiersema 《Euphytica》1955,4(3):197-205
Summary Scorch is a soilborne disease of flax which as far as known only occurs in the Netherlands, Belgium and Northern France. Due to the publication of Marchal (1900) the fungus Asterocystis radicis
de Wild had for a long time been considered as the causal organism. In later years, however, Dutch investigators (v. d. Meer, 1928, and Diddens, 1931) proved that the disease is caused by the fungus Pythium megalacanthum
de Bary and that Asterocystis is quite harmless to flax.The only way of controlling the disease has been the breeding of resistant varieties. As early as 1888 Prof. L. Broekema established that resistance occurs and attempted to raise scorch-resistant varieties. In later years also other investigators and breeders worked on the same problem.The breeding for flax scorch resistance forms part of the working programme of the S.V.P. (Foundation for Agricultural Plant Breeding). Though different isolates of the scorch-fungus were tested by the author, no physiological specialization was found. He evolved a laboratory method for investigating flax scorch resistance and studies the heredity of the resistance. On page 204 the resistance of some varieties is expressed n relative figures.It is attempted to promote breeding work of Dutch private breeders by providing them with resistant populations and lines.Vlasbrand is een bodemziekte welke, voor zoverre bekend, alleen voorkomt in Nederland, België en Noord-Frankrijk. Op grond van de publicatie van Marchal (1900) werd de schimmel Asterocystis radicis
de Wild lange tijd als de veroorzaker van deze ziekte beschouwd. In latere jaren bewezen Nederlandse onderzoeksters (v. d. Meer, 1928 en Diddens, 1931) echter dat de ziekte door de schimmel Pythium megalacanthum
de Bary veroorzaakt wordt en dat Asterocystis ongevaarlijk is voor vlas.Het kweken van resistente rassen vormt de enige mogelijkheid de ziekte te bestrijden. Prof. L. Broekema stelde reeds in 1888 vast, dat resistentie voorkomt en trachtte vlasbrand resistente rassen te kweken. In latere jaren legden ook anderen zich hierop toe.Het kweken op vlasbrand resistentie vormt een onderdeel van het werkprogramma van de S.V.P. Hoewel verschillende isolaties door de schrijver onderzocht zijn, werd geen physiologische specialisatie aangetroffen. Hij werkte een laboratoriummethode uit voor onderzoek op vlasbrandresistentie en bestudeert de erfelijkheid van de resistentie. Op blz. 204 is de resistentie van enige rassen in verhoudingscijfets uitgedrukt.Door de Nederlandse kwekers te voorzien met resistente populaties wordt getracht de kweekarbeid te bevorderen. 相似文献
5.
J. M. Andeweg 《Euphytica》1956,5(2):185-195
Summary Scab caused by the fungus Cladosporium cucumerinum, may cause serious damage to frame cucumbers. Bulbosan (trichlorotrinitrobenzene) is an effective chemical means of control. Between 1945 and 1954 this German fungicide could not be supplied, and, as a result, the need for resistant varieties became very great.Before 1920 scab-resistance in pickling cucumbers was already known to Dutch growers. Selection started around 1920 on the initiative of W. G. v. d. Kroft and resulted in scab-resistant pickling cucumbers of which Baarlose Nietplekker VI is still widely grown. In 1948 G. W. v. d. Helm (Exp. Garden at Sloten) started breeding a scab-resistant yellow slicing cucumber destined for gardeners in the neigh-bourhood of Amsterdam. The resistant variety Highmoor was used as one parent. In 1954 the yellow variety Vios and the white variety Mabro were introduced. In 1952 G. W. v. d. Helm at the Exp. Garden Sloten, and J. M. Andeweg at the Institute of Horticultural Plant Breeding, Wageningen, simultaneously started breeding green scab-resistant frame cucumbers, using Highmoor as the resistant parent. In 1955 the experimental garden at Sloten introduced the scab-resistant green slicing cucumbers Amato and Proso, while in 1956 the Institute of Horticultural Plant Breeding introduced the scab-resistant green slicing cucumber Esvier. In 1953 seed of 2 first-backcross populations was supplied by the Institute to seed growers. At present intensive breeding for scab-resistance is also being carried out by a number of Dutch seed growers.Scab-resistance depends on one dominant gene; and young plants can readily be tested for resistance. Consequently a backcross scheme can easily be carried out. Rapid breeding is possible because at least 2 cultures can be carried out yearly. If necessary, cuttings of promising plants can be taken. Before and after artificial pollination the flowers can be tied up with raffia. It is simpler, however, to pinch the flowers with a special stainless clip as originally used for grafting cucumbers.The uniform fruit colour of the Dutch green frame slicing cucumbers is a recessive character; the fruit length of the Dutch varieties is dominant. 相似文献
6.
Summary A genetic diversity analysis in a collection of 171 non-restorer lines of sorghum (Sorghum bicolor (L.) Moench) using D2 technique and canonical variate analysis indicated that considerable variation in grain yield has been added to the collection by the addition of lines derived from random mating populations. The efficiency of D2 and canonical variate techniques in distinguishing extremely diverse genotypes was confirmed. However, the two techniques showed weak correspondence in their clusters. The F1 hybrids of 15 diverse lines exhibited no relationship between heterosis or per se performance of crosses and diversity in their parents. Therefore, traditional plant breeding methods are being advocated.Approved by ICRISAT as Journal Article no. 435. 相似文献
7.
S. S. Maan 《Euphytica》1977,26(3):601-613
Summary
Triticum aestivum L. em Thell. (2n=42; AABBDD), and T. durum
Desf. (2n=28; AABB) genomes were substituted into the cytoplasms of Aegilops mutica
Boiss. (2n=14; MtMt), Ae. heldreichii
Holzm. (2n=14; MM), Ae. uniaristata
Vis. (2n=14; MuMu), and Ae. ovata L. (2n=28; CuCuMoMo), to identify the M-genome diploid cytoplasm donor of Ae. ovata. Substitution of the T. durum genome into Ae. uniaristata cytoplasm resulted in a large proportion of shriveled inviable seeds. A few plump viable seeds were obtained all of which produced male-sterile plants having one univalent or telocentric chromosome from Ae. uniaristata. The T. aestivum plants having Ae. uniaristata or Ae. mutica cytoplasms were fertile. However, Ae. mutica was similar to Ae. ovata in the induction of delayed maturity and tall robust growth habit to the T. durum and T. aestivum plants. Cytoplasms of the other C- and M-genome diploids Ae. umbellulata
Zhuk. (2n=14; CuCu) and, Ae. heldreichii (2n=14; MM) earlier had been shown to differ from that of Ae. ovata. Therefore, Ae. mutica is the most likely cytoplasm and M-genome donor to Ae. ovata. 相似文献
8.
Summary The inheritance of the dwarf character was studied in F1-seedling populations arisen from crosses between diploid Polyantha cultivars and the diploid dwarf species R. chinensis minima (Sims) Voss. Dwarfness is controlled by a single dominant gene D. R. chinensis minima and its dwarf descendants are heterozygous for D, while polyanthas are homozygous for d. The origin of R. chinensis minima and its potential for breeding new pot roses are discussed. 相似文献
9.
J. Dancer 《Euphytica》1986,35(1):125-128
Summary The preselection test as used in the Kenya arabica coffee breeding program was critically examined prior to use in a similar program in Uganda, since the criticism by Van der Graaff (1982) of the an der Vossen et al., scaling technique for measurement of seedling resistance to Colletotrichum coffeanum may alter the interpretation of results.The published data were re-analysed using non-parametric statistical techniques and it is concluded that, despite the criticism, the method appears to give satisfactory results. It is suggested however, that the mode of the distribution obtained by the selection test be considered as a suitable alternative to the mean in the interpretation of results. 相似文献
10.
M. M. Anderson 《Euphytica》1971,20(3):422-426
Summary When plants of R. ussuriense
Jancz. and two R. nigrum var. sibiricum
E. Wolf. cultivars Rus and Narjadnaja were exposed to infestation by the black currant gall mite (Phytoptus ribis
Nal.) typical galled buds were not formed but damage was caused to meristematic tissues of the buds. Mites were not found in buds during the winter and the plants also remained free from symptoms of reversion virus. Progenies from crosses between these mite-resistant forms and susceptible cultivars indicated that resistance is controlled by a single dominant gene designated P.The above species readily form fertile hybrids with cultivars of black currant and should be useful sources of mite resistance in a breeding programme. 相似文献
11.
S. T. Thul R. K. Lal A. K. Shasany M. P. Darokar A. K. Gupta M. M. Gupta R. K. Verma S. P. S. Khanuja 《Euphytica》2009,168(2):189-196
Phenotypic divergence among the 24 accessions belonging to a collection of six species of Capsicum from different geoclimatic regions available in field gene bank of CIMAP, Lucknow, India, was quantified by multivariate
analysis for 12 quantitative and qualitative traits. Based on their values, all 24 accessions were grouped into six clusters
such that the genetic stocks within cluster had smaller D
2 values among themselves than those belonging to different clusters. The accessions of Capsicum annuum were distributed in different clusters in morphotyping representing different species, suggesting that taxonomic characteristics
are not always related to agronomic traits. No parallelism/association was found between geographical and phenotypic diversity.
Accessions 15 and 23 (clusters V and VI, respectively) had distinct identity. The three characteristics that played the greatest
role in differentiation were fruit diameter, number of fruits per plant, and leaf diameter, which can be utilized as conventional/morphological
markers for the improvement of chilli yield and obtaining good segregants in chilli breeding programs. 相似文献
12.
H. De Haan 《Euphytica》1957,6(2):149-160
Summary In 1886L. Broekema (Wageningen) laid the foundation for wheat breeding in the Netherlands. He succeeded in breeding Wilhelmina wheat (1901) and later Juliana, among other varieties.About the same timeJ. H. Mansholt (Westpolder) andDr. O. Pitsch (Wageningen) started their wheat breeding programmes.It should be stated that these pioneers practised line selection in hybrid populations from the very beginning.Among the other wheat breeders mention should be made ofDr. R. J. Mansholt (Westpolder) who, among other varieties, developed Wilobo and Lovink winter wheat and Van Hoek and Mansholt Witte spring wheat. The Breeding Station C.B. (Hoofddorp) bred the variety Staring,M. Rademakers (Bant, N.E. Polder) Mado, the Seed Company Wiersum (Groningen) Titan, Demeter and Tavero.It appears from the varietal ranges (Figs. 6 and 7) that at present foreign varieties are widely grown. However, wheat breeding in the Netherlands has not fallen asleep; at some breeding establishments large-scale breeding programmes are under way. 相似文献
13.
V. F. Dorofeev 《Euphytica》1969,18(3):406-416
Summary Hybrids naturally arising between Triticum species and between Triticum species and species of Secale and Aegilops are found in wheat fields in Transcaucasia. This continuous exchange of genetic material will yield new genotypes which may be useful in breeding.This active source of the origination of new botanical (sub)varieties results in a great diversity of species and varieties which led Vavilov to conclude that Transcaucasia is centre of origin of several Triticum species and varieties. 相似文献
14.
Summary Eighty-five accessions of Lycopersicon esculentum and related species were tested for resistance to the glasshouse whitefly, Trialeurodes vaporariorum
Westw. High levels of resistance were found in L. hirsutum, L. hirsutum glabratum and Solanum pennellii. In other species, too, some resistance was observed. A breeding program is in progress. 相似文献
15.
Breeding cassava for resistance to cassava mosaic disease 总被引：4，自引：0，他引：4
Summary Cassava mosaic disease (CMD) is one of the most serious and widespread diseases throughout cassava growing areas in Africa, causing yield reductions of up to 90%. Early research on breeding of cassava (Manihot esculenta
Crantz) for resistance to CMD in Africa is reviewed. Changes in population size and in activity of the white-fly vector to CMD (Bemisia tabaci
Genn.) in relation to changes in environmental conditions such as amount and distribution of rainfall, light intensity and temperature are discussed in relation to screening for resistance to CMD. Over the past eight years, significant progress has been made at the International Institute of Tropical Agriculture (IITA). Resistance to CMD has been successfully incorporated into high yielding cultivars of acceptable quality. The CMD resistant material has been evaluated and many promising clones have been selected in various countries in tropical Africa and India. The resistance has been effective in those countries. 相似文献
16.
Bacterial wilt of alfalfa (Medicago sativa L.) caused by Corynebacterium insidiosum
(McCull) Jensen was unknown in Italy until 1957. The authors established in that year in the province of Bologna this dangerous disease in 2–3 year-old stands of alfalfa which appeared uniformly and extensively thinned.They started a breeding programme with the use of bacterial wilt resistant material from the U.S.A., while also studies on methods of testing for resistance under Italian conditions are in progress. 相似文献
17.
A. C. Zeven 《Euphytica》1969,18(2):286-292
Summary In an old logbook by L. Broekema about his wheat breeding work notes were found on the segregation for the characters chaff colour, awning and pubescence of the glume, in the F2 of the cross Dikkop (white chaff-awnless-hairy glume) x Blé d'automne rouge barbu (red chaff-awned-smooth glume). The first variety was better known as Rough-chaffed Essex. The F2's were grown at Wageningen in 1887. Later Broekema calculated the ratios between the alternatives per character. It is impossible to conclude whether he did this before or after the rediscovery of the laws of inheritance in 1900.
Broekema was troubled with the classification of the intermediate types for colour of chaff and awnless or awnleted. This may have resulted in the observation that present 2 give a significant ratio only for pubescence of the glume.It is concluded that Broekema could not have used his figures for a possible rediscovery of the laws of inheritance, but that his knowledge of true-to-seedness for white chaff plants and for smooth glumed plants may have stimulated others to investigate this matter. 相似文献
18.
Cellular thermotolerance in terms of cellular membrane thermostability is often implied as an indication of crop heat tolerance and it is therefore considered as a possible selection criterion for heat tolerance. While there is ample genetic variability for cellular thermotolerance in wheat and other crop plants its relations to yield under heat stress is not sufficiently established. This study was performed to assess the genetic relations in wheat between cellular thermotolerance and yield under heat stress. In one study the co-segregation among cellular membrane thermostability (CMS), yield under chronic heat stress and yield under non-stress conditions was evaluated in a random inbred line (RIL) population of a cross between heat resistant (Danbata) and heat susceptible (Nacozari) cultivars. In a second study the same association was evaluated for yield under heat stress in 49 F7 breeding lines randomly selected from a breeding program. CMS was assayed in growth chamber grown and heat-hardened seedlings. Yield was evaluated under Mediterranean summer irrigated conditions where chronic heat stress caused a reduction in mean yield of the RIL population by 47% as compared with the normal winter growing conditions (non-stress). The RILs varied significantly (p<0.05) for CMS, biomass and yield under stress and non-stress conditions. The two parent cultivars did not differ in biomass or yield under non-stress (winter) conditions but they widely differed for both traits under heat stress. Yield of RILs under heat stress was well distributed between the extreme values of the parent cultivars. There was a significant RIL by season interaction for biomass (F = 9.74; p<0.0001) and yield (F = 10.08; p<0.0001), indicating specific adaptation to heat stress of certain lines in terms of their productivity. Broad-sense heritability for yield was high and nearly the same in the winter (h
2=0.71)and the summer (h
2=0.67). Broad-sense heritability for CMS was high (h
2=0.74). CMS was positively and significantly (p<0.01) correlated across 98 RILs with biomass (r = 0.60* *) and yield (r = 0.53**) under stress but rot with biomass or yield under non-stress conditions. The 49 breeding lines varied significantly (p<0.01) for CMS and yield under chronic heat stress in the summer season. CMS and yield were significantly correlated (r = 0.56**) across lines. Overall the associations between CMS and yield under heat stress were reasonably strong and significant but not perfect. Other factors besides cellular thermostability may support yield under heat stress. CMS alone cannot be used as the exclusive selection criterion for heat tolerance in wheat breeding. lt may be valuable as a supplemental criterion in the final breeding stages or as a rough selection tool to reduce a large population into the most likely heat tolerant core at the early stages of the breeding program. 相似文献
19.
Summary Many conventional hard red spring wheat (Triticum aestivum L. em Thell) lines, including several North Dakota cultivars, carry a gene (or genes) which restore partial male fertility to male sterile plants with Triticum timopheevi
Zhuk. cytoplasm. Since this gene has no fertility restoration function in T. aestivum cytoplasm, the postulation can be made that it is being retained in conventional lines because of pleiotropic effects, favorable linkages or chance. The research reported in this paper examined these possibilities. Forty F6 lines, derived from a single F2 plant which was heterozygous for a gene (or genes) for partial fertility restoration, were evaluated for two years in a yield trial planted at Fargo, North Dakota. The 40 lines were testcrossed to a male sterile line having T. timopheevi cytoplasm, and the mean seed set of testcrosses was used as a measure of a line's fertility restoration potential. Twenty-seven lines had the gene for partial fertility, and 13 lines apparently lacked this gene. The 40 lines differed for heading date, anther extrusion, plant height, grain yield, 200-kernel weight, test weight, and grain protein percentage. However, comparisons of lines having the restorer gene with those lacking the gene did not provide any obvious explanation for the retention of the partial fertility restorer gene in the breeding stocks of the North Dakota conventional hard red spring wheat breeding program. The possibility that the restorer gene was linked with genes for resistance to stem rust or leaf rust also was evaluated by testing lines for their reaction to several races of rust. No conclusive association was found.Contribution from the Agric. Exp. Sta., North Dakota State University, Fargo, ND 58105, Journal Article no. 相似文献
20.
Summary Natural out-crossing imposes considerable costs and inefficiencies in breeding, evaluation and commercialization of pigeonpea (Cajanus cajan (L.) Millsp.). This note reports identification of a modification of floral morphology which inhibits cross-fertilization. Floral morphology and possible mechanisms of action of this character are discussed.On leave from International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). Hyderabad, India. 相似文献