Showing papers by "International Potato Center published in 1989"
TL;DR: Evidence shows that this novel gene was transcribed and translated within the transformed plant and integration of the gene into the plant genome and its expression into mRNAs and HEAAE-proteins have been demonstrated using Southern, northern and western analysis.
47 citations
TL;DR: The present results demonstrated that the androgenetic ability could be transferred through sexual crosses, making it possible to successfully apply anther culture to other useful genetic material lacking this ability.
Abstract: A diploid potato clone AH 78/8015.37a with androgenetic ability was crossed with a root-knot nematode resistant diploid clone 381320.23 which did not have this ability.Among 19 F1 progenies tested a wide range of continuous variability was found for androgenetic capability. Four F1 clones with different level of embryo formation capability were backcrossed to 381320.23 to produce 4 F1BC1 families to further clarify the genetic control of androgenetic capability.From the wide range of continuous variability for androgenetic ability observed, it can be inferred that this character is controlled by more than one major gene.The occurrence of plants with androgenetic ability derived from parents both lacking this character, indicated that the androgenetic ability is controlled by recessive genes or results from complementation of various factors singly present in the parents. The present results demonstrated that the androgenetic ability could be transferred through sexual crosses, making it possible to successfully apply anther culture to other useful genetic material lacking this ability.
29 citations
TL;DR: The methodology applied by the International Potato Center for in vitro maintenance is described and new research now being undertaken to study the genetic stability of these storage methods are discussed.
Abstract: The last decade has seen growing awareness of the value of germplasm conservation.In vitro maintenance of germplasm can offer many advantages as a complement to field maintenance. The International Potato Center (CIP) has actively researched a wide range of methods for effectivein vitro maintenance in its large potato germplasm collection. This review describes the methodology applied by CIP and discusses new research now being undertaken to study the genetic stability of these storage methods.
26 citations
TL;DR: Through these research efforts, mainly based on a population breeding strategy, new sources of genetic variability for yield, tuber quality factors, and pest, disease, and stress resistance or tolerance have been identified and the utilization of these new breeding resources has already started to produce results.
Abstract: The genetic basisof Solanum tuberosum ssp.tuberosum has been discussed focusing on the importance of increasing its genetic variability. A review of the work on germplasm enhancement, using both cultivated, primitive and wildSolanum species, carried out by several institutions, has been made. Through these research efforts, mainly based on a population breeding strategy, new sources of genetic variability for yield, tuber quality factors, and pest, disease, and stress resistance or tolerance have been identified. The utilization of these new breeding resources has already started to produce results. In the last few years at least 30 new varieties, carrying resistance to one or more pests, diseases, or stresses, have been released in several countries.
19 citations
TL;DR: In this article, the authors applied Dolomitic lime to an Ellzey sand (sandy, siliceous, hyperthermic Arenic Ochraqualfs) at rates of 0.0, 2.2, 4.8, 5.4, 6.1, and 6.5 during the 5 yr of the study.
Abstract: (...) Dolomitic lime was applied to an Ellzey sand (sandy, siliceous, hyperthermic Arenic Ochraqualfs) in 1977 at rates of 0.0, 2.2, 4.5, and 9.0 Mg ha −1 , and resulted in average soil pH levels of 4.8, 5.4, 6.1, and 6.5 during the 5 yr of the study. In 1978 four rates of P were superimposed on lime treatments to establish a range of residual soil P levels for use in subsequent years of the study (...)
18 citations
TL;DR: Increase of susceptibility to PLRV infection caused by pre-infection with PVX and PVY seems to be a general phenomenon among potato cultivars that becomes more evident in resistant genotypes.
Abstract: The effect of infection with some viruses on the resistance to potato leafroll virus (PLRV) was studied in clones with different levels of resistance. Clones known to have high levels of resistance to PLRV infection showed a reduction of their resistance in plants previously infected with potato viruses X and Y (PVX and PVY). However, pre-infection with potato virus S did not alter their level of resistance to PLRV infection. Conversely, in clones hypersensitive to PVX and PVY, prior infection with PLRV abolished the typical necrotic reaction and the plants were not infected with either PVX or PVY. Increase of susceptibility to PLRV infection caused by pre-infection with PVX and PVY seems to be a general phenomenon among potato cultivars that becomes more evident in resistant genotypes. The practical importance of PVX and PVY infections during selection of PLRV resistant genotypes is discussed. The stability of PLRV resistance under field conditions seems dependent upon the cultivar and type of resistance to PVX and PVY.
18 citations
TL;DR: Reducing the spacing between rows and maintaining the same sprout density was more effective in increasing yields from small seed tubers than increasing sproutdensity from 20 to 40 sprouts per m2 by reducing plant spacing within the row.
Abstract: Small seed tubers of 1–5 g, 5–10 g and 10–20 g were planted at the same sprout densities as standard size seed tubers of 40–60 g in order to give similar stem densities Early ground cover by foliage, total yield, and yield of tubers >45 mm were consistently greater in plots planted with larger seed tubers The effect of seed tuber size on yield and tuber number per stem varied between years but 1–5 g seed tubers always gave lower yields per stem than larger seed tubers Reducing the spacing between rows from 90 cm to 60 cm and maintaining the same sprout density was more effective in increasing yields from small seed tubers than increasing sprout density from 20 to 40 sprouts per m2 by reducing plant spacing within the row
17 citations
TL;DR: Large seeds contained higher levels (% dry weight) of total proteins, ethanol soluble proteins and alkali soluble proteins than small seeds and they germinated faster and had the highest percentage of germination.
Abstract: Seeds of an open pollinated crop of potato (Solanum tuberosum L.) TPS-2, cv. Kufri Jyoti, were graded into four sizes. There were significant differences between grades for 100-seed weight, the concentrations of total proteins and ethanol soluble proteins, and total lipids and phospholipids.
13 citations
TL;DR: The use of nondormant seed may be a requirement for both effective priming and sowing of potato crops via true seed through presowing in water or gibberellic acid.
Abstract: The effects on germination and early seedling growth of presowing true potato seed in water or gibberellic acid (GA) at 1500 ppm and of priming in −1.0, −1.25 and −1.5 MPa solutions of KNO3+K3PO4 were studied using 30, 18, 6 and 3/4 month-old seed. The influence of light during presowing on the effectiveness of treatments was also investigated.
11 citations
TL;DR: A total of 115 out of 512 genotypes combined resistances to both Fo and Fs were identified, and 59 genotypes that combine resistance toErwinia andFusarium were also identified.
Abstract: Tubers from open pollinated progenies of 15 cultivars ofS. tuberosum ssp.andigena were evaluated separately for their reactions toFusarium andErwinia. The materials inoculated withF. oxysporum (Fo) showed a range of 8 to 29% (mean= 18.6%) of genotypes with no rotting symptoms. In inoculations withF. solani(Fs), the range was from 6 to 41% (mean=24.3%). High levels of resistance toE. chrysanthemi (Ech) soft rot were observed in 7 out of the 15 progenies evaluated. A range from 5 to 19% (mean=10.1%) of genotypes with cylindrical rot of less than 1.9 mm was observed. A total of 115 out of 512 genotypes combined resistances to both Fo and Fs. Moreover, 59 genotypes that combine resistance toErwinia andFusarium were also identified. Seven of these were resistant to Fo and Ech, 25 to Fs and Ech, and more important, there were 27 genotypes resistant to Fo, Fs, and Ech.
11 citations
TL;DR: The stage of berry development at harvest was found to be an important factor influencing seed performance during early seedling growth and the association of vigor responses to increasing seed maturity was dependent on the treatment and the cross.
Abstract: True potato seed of Atzimba × R128.6 (cross A) and Serrana x R128.6 (cross B) were tested to measure the effects of increasing berry development on seedling vigor. The seed were harvested at 6, 8, 10, and 12 weeks post-pollination and evaluated after about 6 months of storage. Influences of two pre-sowing treatments were also examined. The seed were soaked for 5 days in solutions of 1) KNO3 + K3PO4 at −1.0 MPa (priming), and 2) gibberellic acid at 50 ppm (GA50); rinsed seed and untreated seed served as controls. After treatment, all lots were dried to uniform moisture and stored for 5 days before sowing in soil media under screenhouse conditions. Seed vigor levels were measured by 1) rate of emergence, 0–10 days after sowing (d.a.s.), 2) percentage of emergence, 10 d.a.s., and 3) seedling dry weight, 17 d.a.s. The stage of berry development at harvest was found to be an important factor influencing seed performance during early seedling growth. The association of vigor responses to increasing seed maturity was dependent on the treatment and the cross. For cross A, most treatment responses were linear, and also curvilinear, particularly the priming treatment. Cross B responses were similar, although less marked, and the control treatments were more affected by increasing seed maturity. Maximum vigor ratings in both crosses were estimated to be in seed harvested at about 11 weeks post-pollination. However, the results of a preliminary test suggested that the slightly lower vigor in 12-week seed was due to a higher level of seed dormancy. Cross A was more vigorous than B, and priming was the most effective pre-sowing treatment used and GA50 the least.
TL;DR: True potato seed progenies from diverse genetic backgrounds were evaluated in three environments, both as transplants and as first generation seed tubers, finding first generation seeds had superior yields compared to transplants, especially at the high and low elevation locations and gave yields similar to the local cultivar.
Abstract: True potato seed progenies from diverse genetic backgrounds were evaluated in three environments, both as transplants and as first generation seed tubers. Plant growth from transplants was extremely sensitive to daylength and temperature. The mid-elevation site with minimum/maximum temperatures of 17/27 C and a 12 to 12.7 h daylength favored rapid canopy growth and acceptable tuber yields (up to 28 t/ha) for most progenies evaluated. Under cooler, shorter, daylength growing conditions, seedlings would tuberize rapidly, particularly those of a predominatelyS. tuberosum L. background. Tuber yields from transplants generally were much lower than those from the local cultivar grown from seed tubers but had many more tubers, which is favorable as an efficient way to produce seed tubers for replanting. First generation seed tubers had superior yields compared to transplants, especially at the high and low elevation locations and gave yields similar to the local cultivar. On the basis of tuber yield, tuber size and uniformity of TPS progenies, the following are some of the superior parental lines: I-931, I-1035, CFK69.1, Atzimba, Serrana, LT-7, 7XY.1, (BR63.74x Katahdin) .7 and .9, 378015.3 and .16.
TL;DR: Seed cutting is feasible in reducing seed rates and for more effective use of large, expensive seed tubers for potato-production cost in the warm tropics.
TL;DR: The range of this pest from Northern Africa into the central regions of the continent is extended and data illustrates the severity of infestations in Zaire, Burundi and Kenya.
Abstract: Extensive trapping with sex pheromones was done in the East African region in 1987–88 to determine the distribution of the potato tuber moth The results obtained extend the range of this pest from Northern Africa into the central regions of the continent Data illustrates the severity of infestations in Zaire, Burundi and Kenya
TL;DR: A new wild Peruvian diploid tuber-bearing species ofSolanum, S. salasianum (seriesConicibaccata, Sect.Petota) from the moist montane forest near Monocanca, province Pachitea, department of Huanuco is described and illustrated.
Abstract: A new wild Peruvian diploid (2n=2x=24) tuber-bearing species ofSolanum, S. salasianum (seriesConicibaccata, Sect.Petota) from the moist montane forest near Monocanca, province Pachitea, department of Huanuco is described and illustrated. It is named in honor of my assistant, agronomist Alberto Salas Lopez.
TL;DR: A new diploid wild Peruvian species of Solatium, S. amayanum (series Tuberosa, Sect.Petota), from the Andean region of province Tayacaja, department of Huancavelica, is described, illustrated, and compared with S. medians possibly its closest relative.
Abstract: A new diploid (2n=2x=24) wild Peruvian species ofSolatium, S. amayanum (series Tuberosa, Sect.Petota), from the Andean region of province Tayacaja, department of Huancavelica, is described, illustrated, and compared withS. medians possibly its closest relative. It has been named in honor of my assistant, Mr. Jesus Amaya Castillo.