An evaluation of the use of dihaploids and unreduced gametes in breeding for quantitative resistance to potato pathogens

1982 ◽  
Vol 99 (1) ◽  
pp. 79-83 ◽  
Author(s):  
M. J. De Maine
Keyword(s):  
Quantitative Resistance ◽  
Field Tests ◽  
Unreduced Gametes ◽  
Cyst Nematode ◽  
Potato Cyst Nematode ◽  
Resistance Testing ◽  
Blight Resistance ◽  
The Mean ◽  
Potato Pathogens ◽  
Made In

SUMMARYIn a breeding programme to combine quantitative resistance to two important potato pathogens, Phytophthora infestans causing late blight in foliage and Qlobodera pallida (the cream potato cyst-nematode), tetraploid (4 ×) off spring were obtained by crossing dihaploids, mainly as females, with tetraploids. Glasshouse and field tests in the first and second tuber-years showed that most of the off spring of highly blight-resistant dihaploids had high resistance to P. infestans. Two such dihaploids, PDH 182 and PDH 247, crossed with a tetraploid selected for high general combining ability for potato cyst-nematode (PCN) resistance, gave off spring all of which were highly blight resistant. About one third also had high PCN resistance.Detached leaflet tests were used for rapid blight resistance screening of other progenies from dihaploid × 4 × crosses in their seedling year. Differences were found in the effects of 4 × parents on the mean resistances of progenies from blight-resistant dihaploids.The results also showed differences between dihaploids in their effectiveness in transmitting blight resistance to 4 × offspring. This could be due to differences in the mode of unreduced female gamete formation, i.e. first division restitution or second division restitution (SDR). If all the unreduced gametes were produced by SDR, the differences could be due to differences in homozygosity between dihaploids with respect to blight resistance genes.The dihaploid × 4 × crosses gave few offspring per pollination. The few seedlings obtained may be offset by a higher frequency with the required characters. Since fewer seedlings would have to be grown in order to find the required combination of characters, savings could be made in planting and resistance-testing facilities over those required in conventional breeding.The tetraploid hybrids obtained can be used in a second cycle of breeding in three ways simultaneously: by crossing with other tetraploids, by crossing with dihaploids selected for complementary characters and to produce dihaploids with combined resistances.

scholarly journals Population changes of the potato cyst nematode (Giobodera rostochiensis) during irregular crop rota­tion

1999 ◽  
Vol 35 (No. 4) ◽  
pp. 125-130
Author(s):  
J. Šedivý
Keyword(s):  
Potato Cultivar ◽  
Cyst Nematode ◽  
Potato Cyst Nematode ◽  
Potato Cultivars ◽  
Pig Manure ◽  
Resistant Cultivars ◽  
Increasing Trend ◽  
Negative Effect ◽  
Soil Infestation ◽  
The Mean

For a period of 17 years, changes in the n umber of potato cyst nematode (PCN) cysts in the soil and in their contents were studied in two fields with an irregular crop rotation and growing resistant and susceptible potato cultivars. In all years, numbers of cysts per I 00 g of soil were higher at Skorkov (S) than at Ot radovice (0). At the beginning of the experiment, the percentages of empty PCN cysts were 30 and 28%, respectively, but they increased to 92.5 and 94.6%, respectively, by the end of it. The remaining cysts contained dead eggs/larvae and empty egg cases. Thus, the number of cysts per I 00 g of soil cannot be used to estimate the degree of soil infestation with the PCN without also knowing the number of viable stages in the cysts. When the experiment started the mean number of viable eggs/larvae per cyst was 62.7 in fields and 51.3 in field 0; no viable stages of the pest were found at the end of the experiment. Parallel to the decline in the number of viable eggs/larvae per cyst, the numbers of cysts with viable contents also declined in both fields. The mean number of dead eggs/larvae per cyst showed considerable variation in the course of the experiment.  In fields it varied within a range of 1 5.9-69.4 individuals per cyst. Over the years the number of empty egg cases per cyst showed an irregular increasing trend. In field S their number varied from 34.9 to 1 97.5 per cyst. In field 0 from 46.3 to 218. No unequivocal negative effect of cropping resistant potato cultivars on the number of PCN cysts in the soil has been ascertained. In most years. The cropping of resistant cultivars was followed by an increased number of empty cysts in soil samples in both experimental fields.  The effect of growing resistant cultivars on the number of viable eggs/ larvae was negative in both fields, resulting in decreased mean numbers of viable individuals per cyst. The mean number of dead eggs/larvae per cyst was variable.  The number of empty egg cases was usually higher after the harvest of a resistant potato cultivar. The numbers of empty cysts and those with dead contents increased distinctly after an application of pig manure prior to growing the resistant cultivar and in subsequent years. The mean number of cysts in the soil, and of viable stages in the cysts also declined after a crop of rye. Regula r cropping of resistant potato cultivars at 3-year intervals, once interrupted by growing a susceptible plant cultivar, decreased the occurrence of viable stages of the PCN below the detectable level.

Assessing potato seedling progenies for resistance to the white potato cyst-nematode

1982 ◽  
Vol 99 (1) ◽  
pp. 67-70 ◽  
Author(s):  
M. S. Phillips ◽  
M. F. B. Dale
Keyword(s):  
North Carolina ◽  
Cyst Nematode ◽  
Potato Cyst Nematode ◽  
Breeding Value ◽  
Potato Seedling ◽  
White Potato ◽  
Seedling Test ◽  
The Mean ◽  
Half Diallel

SUMMARYA bulk seedling test is described which can be applied shortly after completion of a crossing programme. The test assesses resistance to G. pallida in progeny derived from crossing programmes involving S. luberosum, S. vernei and S. tuberosum spp. andigena. It provides good estimates of both the mean level of resistance within progenies and the breeding value of the parents. The test was applied to a crossing schedule involving a half-diallel and a North Carolina 2 design utilizing a range of material. The results and their implications are discussed.

scholarly journals Current Distribution of Golden Potato Cyst Nematode Globodera rostochiensis (Tylenchida, Heteroderidae) in Ukraine

Zoodiversity ◽  
2021 ◽  
Vol 55 (2) ◽  
pp. 167-174
Author(s):  
O. I. Borzukh ◽  
D. D. Sygareva ◽  
O. L. Fedorenko ◽  
T. I. Bondar ◽  
V. V. Kornyushin ◽  
...  
Keyword(s):  
Average Rate ◽  
Cyst Nematode ◽  
Potato Cyst Nematode ◽  
High Rate ◽  
Golden Nematode ◽  
Small Areas ◽  
Nematode Abundance ◽  
The Mean ◽  
Autonomous Republic ◽  
Private Farm

Globodera infestation was evaluated in soils of private farm plots in Chernihiv and Kyiv regions of Ukraine in 2017–2018. Soil samples were taken at 88 farms, 15.02 ha in total, in 11 settlements of 6 districts. The nematode abundance in the examined areas was graded as follows: less than 1000 eggs + larvae/100 cm3 — low rate of infestation; 1000–5000 eggs + larvae/100 cm3 — average rate; more than 5000 eggs + larvae/100 cm3 — high rate. 85.4 % of study area is infested with the golden potato cyst nematode. The mean abundance of pest was 3331 (15–23,237) eggs+larvae/100 cm3: including 8730 (91–21,486) eggs+larvae/100 cm3 in Kyiv Region and 1829.6 (15–23,237) eggs+larvae/100 cm3 in Chernihiv Region. The highest number of assessed plots per district (29) was in Koryukivsky District, and the mean abundance of G. rostochiensis (Rо-1) was 1549 (20–15,757) eggs + larvae/100 cm3e+l/100cm3. We also analyzed the results of golden nematode monitoring conducted by the State Service of Ukraine for food safety and consumer protection in 2018. According to those, the golden nematode is found in 18 regions of Ukraine. In most of those (14 regions), the pest infests rather small areas, less than 500 ha. Globodera is not recorded in the other 7 regions of Ukraine and Autonomous Republic of Crimea for now.

Coronary Care in a General Hospital

1971 ◽  
Vol 16 (3) ◽  
pp. 173-182 ◽  
Author(s):  
Gavin Shaw ◽  
Bernard Groden ◽  
Evelyn Hastings
Keyword(s):  
Myocardial Infarction ◽  
Intensive Care Unit ◽  
Intensive Care ◽  
General Hospital ◽  
First Year ◽  
Duration Of Stay ◽  
Before And After ◽  
The Mean ◽  
Coronary Care ◽  
Made In

The establishment, staffing and structure and observations made in the first year of the existence of coronary care in an intensive care unit in a general hospital are recorded. Two hundred and twenty eight patients were admitted during the year in whom the diagnosis of myocardial infarction was confirmed. There were 29 deaths in the unit and 14 deaths occurred in the wards of the hospital after discharge from the unit. 49.1 per cent of the patients were admitted within 4 hours of the onset of symptoms and the mean duration of stay in the unit was 86.5 hours. The type of arrhythmia detected in the unit, and the treatment given to the patients both before and after admission to the intensive care unit are described.

SURGICAL PROCESS RE-ENGINEERING: CARPAL TUNNEL DECOMPRESSION — A MODEL

Hand Surgery ◽  
2004 ◽  
Vol 09 (01) ◽  
pp. 19-27 ◽  
Author(s):  
J. A. Casaletto ◽  
V. Rajaratnam
Keyword(s):  
Carpal Tunnel ◽  
Carpal Tunnel Release ◽  
Procedure Time ◽  
Original Process ◽  
Depth Analysis ◽  
New Process ◽  
Common Operation ◽  
The Mean ◽  
Operative Findings ◽  
Made In

Surgical process re-engineering is a methodology where the entire surgical process is systematically analysed and re-designed. The process starts with mapping of the current process followed by in-depth analysis of the existing process. A new process is drafted with the aim of making the whole procedure more efficient. The new process is then discussed with all the staff involved in the operating room. Following implementation of the process, surgical process re-engineering should ideally be routinely carried out to continuously improve the procedure. We present an example of surgical process re-engineering which we carried out on the procedure of carpal tunnel release. We used carpal tunnel release as a model as it is a very common operation, with predictable intra-operative findings, and the patient is likely to benefit directly from procedure time reduction. A preliminary mapping of three procedures was done followed by a detailed timed mapping of five routine carpal tunnel decompression procedures. The mapped process was analysed in detail and a number of changes were made in the process. After implementing the new process, a further five procedures were mapped and timed again. In comparison to the original process, we achieved a reduction of 20% in the mean procedure time and a reduction of 42% in the number of steps from 66 to 37.

The suppression of tomato defence response genes upon potato cyst nematode infection indicates a key regulatory role of miRNAs

2017 ◽  
Vol 113 ◽  
pp. 51-55 ◽  
Author(s):  
Magdalena Święcicka ◽  
Waldemar Skowron ◽  
Piotr Cieszyński ◽  
Joanna Dąbrowska-Bronk ◽  
Mateusz Matuszkiewicz ◽  
...  
Keyword(s):  
Cyst Nematode ◽  
Defence Response ◽  
Nematode Infection ◽  
Potato Cyst Nematode ◽  
Regulatory Role
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