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PubMed1993

The effect of United States versus New Zealand Angus germplasm on characteristics of crossbred calves.

Blood selenium concentration at birth and growth from birth through finishing were analyzed on progeny from two birth years of Angus bulls of United States (US) or New Zealand (NZ) origin. Dams of the calves were Polled Hereford x Angus crossbreds whose sires had been selected divergently from the national sire summary to be superior (+) or inferior (-) for yearling weight EPD (G) and for total maternal effects (M) on weaning weight. There was no evidence of differences attributable to calf paternity or dam genetic group in concentration of blood selenium in calves at birth. For birth year 1988, progeny of US sires grew nonsignificantly more rapidly than progeny of NZ sires in most life-cycle phases. In 1989 calves, NZ-sired offspring grew nonsignificantly more rapidly than US-sired offspring through a year of age. Averaged across years, preweaning and postweaning growth rates were similar for calves of US and NZ paternity. Divergent selection of the calves' maternal grandsires for yearling weight EPD was successful; calves in +G groups had more rapid gains through 1 yr of age than did calves in -G groups. Also, growth rate through 4.5 mo of age was influenced by divergent selection of maternal grandsires on total maternal weaning weight EPD; calves from +M groups gained more rapidly than calves from -M groups.

Analysis of Variance↗
PubMed1998

Testing of plum germplasm for sensitivity to plum pox.

A long-term orchard experiment with a broad assortment of plum cultivars aimed to screen their sensitivity to plum pox virus (PPV) was established in 1991. For this purpose, 207 cultivars to be artificially infected with PPV at a permanent site were chosen. The serotype M of PPV from a tree of cv. Domestic Prune, which had not been contaminated by other viruses, was used as a source of the infection. Three buds infected with PPV were budded on 1-year-old trees. In the course of experiment the following results were obtained. The highest transmission of PPV was recorded in the first year after infection, when 69.5% of positive trees were detected by enzyme-linked immunosorbent assay (ELISA). After 4 years, the absence of PPV was still detected in 11.2% of the cultivars. These were reinfected with the same source of PPV in 1996. In 1998, there were 92.9% of trees contaminated by sharka. Seven years after infection with PPV, a dieback of 41 trees took place. In the most cases a presence of an ilarvirus in the plant was detected. The PPV infection was not transferred further on cvs Bila trnecka, Francia Naranes, Large Sugar Prune, Reine Claude Diaphane, Renkloda Jandacek, Scoldus, Tarnina x Kirke, Valasska trnecka and K-4. There were 75% of trees fruited in 1997. Only 28 cultivars had no symptoms of PPV on fruits. A statistically significant relationship between the incidence of PPV after the artificial infection and a the presence of prunus necrotic ring spot virus (PNRSV). The presence of PNRSV reduced the transmission of PPV. Relationships between PPV and prune dwarf virus (PDV), and between PPV and (PDV + PNRSV) were not statistically significant.

Agriculture↗
PubMed2001

[Gene analysis of Chinese barley dwarf germplasm resources. II. Location of the dwarf genes on chromosomes].

Twenty dwarf sources of Chinese barley were crossed to a set of marker stocks. Based on the linkage tests with the marker traits and genes, the dwarfing genes in Chinese dwarf barley were located on different chromosomes. Fifteen of the 20 dwarf sources were recessive mono-locus. Among them, BQK carried a pair of dwarfing genes on its short arms of 2(2H) chromosome, linking to the wide outer glume gene w; HZA 77 etc. 10 dwarf sources held dwarfing genes allelic to semi-brachytic gene uz on their long arms of 3(3H) chromosomes respectively; 91G318, 91D27, 11012.2 and JJ had dwarfing genes on their long arms of 4(4H) chromosomes, which linked with the hooded awn gene K. The remaining five dwarf sources were two-locus. Two recessive loci were found to be on 2HS and 4HL respectively in DQQK, ZLL and ZLLQK. A pair of incomplete dominant genes were located on 2HS, and another pair of recessive ones located on 3HL in 1974E. Two recessive loci of Yan 66 were separately located on its 3HL and 4HL.

China↗
PubMedDate not supplied

Routine cryopreservation of kiwifruit (Actinidia spp) germplasm by encapsulation-dehydration: importance of plant growth regulators.

The encapsulation-dehydration protocol was optimized for an in vitro cultured hybrid Actinidia arguta x A. deliciosa. Shoot tips from 14-d reactivated mononodal microcuttings were embedded, transferred to liquid culture medium whose sucrose concentration was daily increased (0.3, 0.5, 0.75 M) and then kept at 0.75 M for 2 or 4 d. Dehydration on silica gel was monitored to 20+/-1.5% residual water content (dry weight basis), allowing direct quenching in liquid nitrogen and rewarming at room temperature. Differential scanning calorimetry analysis underlined the importance of reversible glass transition in shoots for survival. Regrowth ranged from 85% to 95%. Growing shoot tips showed no phenotypic abnormalities. Rooting was also achieved. This method was routinely applied to diploid A. chinensis and A. eriantha, and to several diploid hybrids, yielding over 70% regrowth. A slight decrease in sucrose molarity (0.65 M) allowed tetraploid A. chinensis and A. chrysantha x A. arguta to survive dehydration, but not quenching in LN. For A. deliciosa cv Hayward and cv Tomuri, normal regrowth after cryopreservation was achieved only after modification of the pre- and post-culture media, highlighting the importance of monitoring plant growth regulator balance, principally at the post-thaw recovery step.

Actinidia↗
PubMed2002

Fruit plant germplasm characterisation using molecular markers generated in RAPD and ISSR-PCR.

The genotypes of the strawberry (Fragaria x ananassa), apple (Malus domestica) and Ribes species (R. nigrum, R. rubrum and R. glossularia), maintained in our Institute's collection and used in breeding programs, were screened for DNA markers. Twenty primers for RAPD (among 60 tested) and seven for ISSR (among 10 tested) were chosen as creating polymorphic DNA bands differentiating the investigated genotypes. Based on those identity markers, the genetic distance between genotypes was determined, and their relatedness was estimated. In many cases, both RAPD- and ISSR-based genetic similarity confirmed relatedness connected with biological origin and with the place where the cultivar was developed. However, some diversity connected with the technique used for molecular marker generation was observed. Generally, the similarity values based on ISSR data were higher than those based on RAPD. Parallel study using two data sets seems to enable a reduction in the number of potential mistakes connected with each method's, technical limitations and ensures more precise relatedness determination.

DNA Fingerprinting↗
PubMed2002

[Quality evaluation and utilization of germplasm resources of Magnolia officinalis].

OBJECTIVES: To lay a theoretical foundation for studies on strategies for improvement of Magnolia officinalis and select superior gemplasm resources to meet the demand for modernization, industrialization and internationalization of Chinese medicine. METHODS: Seeds of Magnolia officinalis from 13 main habitats of 7 provinces were collected and strewn in a place of Jingning County, Zhejiang. At the age of seven, 195 samples were collected from the same height of the trunk of 15 individual trees of each provenance, and assayed for effective ingredients with HPLC. RESULTS: Differences in the content of phenols were significant among the seed sources and even greater among individuals within a seed source. CONCLUSIONS: 3 seed sources viz. Wufeng, Hefeng and Enshi of Hubei were obviously superior to other seed sources on account of high contents of magnolol, honokoiol and total phenols. Extension and application of these 3 seed sources is an effective path leading to quality improvement of Magnolia officinalis. With great differences in the content of phenols existing among individuals within each source, there is a big gap between production of medicinal materials by merely using superior seed sources of Magnolia officinalis and the demand of stable and controllable quality for modernization and internationalization of Chinese medicine. But the great difference has laid a material foundation and brought about a great potential for genetic improvement of Magnolia officinalis. Therefore, the superior individuals within a superior seed source are an excellent material for the breeding of Magnolia officinalis.

Biphenyl Compounds↗
PubMedDate not supplied

Development of probabilistic tools to assist in the establishment and management of cryopreserved plant germplasm collections.

A simple method, based on the binomial distribution, is proposed to calculate the probability of recovering at least one (or any other fixed number of) plant(s) from a cryobank sample using four given parameters: the percentage of plant recovery observed from a control sample, pobs, the number of propagules used for this control, n1, the number of propagules in the cryobank sample, n2, a chosen risk for the calculation of a confidence interval for the observed plant recovery, alpha. Using this method, it is possible to assess the number of propagules which should be rewarmed immediately after freezing in order to estimate the plant recovery percentage as a function of the total number of propagules available. It also allows the calculation of the minimum plant recovery percentage to ensure that the probability to recover at least one (or A, with A>1) plant(s) is higher than a fixed probability level, as a function of the control and the cryobank sample sizes. Reciprocally, once the plant recovery percentage has been estimated, it is possible to assess the minimum size of the cryobank sample to obtain a probability to recover at least one (or A, with A>1) plant(s) higher than some fixed level.

Binomial Distribution↗
PubMed2004

[Assesment of genetic diversity of allelopathic rice germplasm based on RAPD and ISSR].

Random Amplified Polymorphic DNA (RAPD) and Inter-simple Sequence Repeat (ISSR) methods were used to detect the genetic diversity of 57 allelopathic rice accessions which were introduced from 10 countries or areas. A total of 12 RAPD primers and seven ISSR primers were indentified with polymorphism among the entries. For RAPD markers, 85 polymorphic bands were produced, percentage of polymorphic bands (PPB) were 69.4%. For ISSR marker, 34 polymorphic bands were generated, PPB were 53.0%. The result from the clustering analysis by UPGMA indicated that those accessions from the same geographical location were clustered into one group. It was also found that some rice accessions with higher allelopathic potential were clustered together, implying that the genes conferring allelopathy in those rice accessions might be isolocus. However, some rice accessions with different allelopathic potential clustered into the same group performed lower level of generic polymorphism which was attributed to oriented selection for other traits in breeding program. The estimates of correlation coefficient of RAPD and ISSR based on the genetic similarity matrices were significantly correlated.

Genetic Variation↗