Potato cuttings as models to study maturation and senescence

Summary Single leaf cuttings with their subtended axillary buds proved to be useful models to study maturation and senescence in potato (Solanum tuberosum L.). Senescence was more rapid if the cultivar was early maturing or if plants were exposed to short days before cuttings were taken. Rooting was decreased by short days before cutting; excision of the buried bud only partially overcame the effects on senescence and rooting. High rates of N to mother plants in the field delayed senescence of cuttings in a way analogous to the delayed senescence of field plants. The tuberization of cuttings from late maturing cultivars was decreased by high rates of N. The color of crisps made from bud tubers was positively correlated with the color of crisps made from ordinary tubers of the same cultivars. Sugar concentrations in bud tubers decreased as cuttings became more senescent and increased after cold storage. Bud tubers harvested while ‘immature’ had greater concentrations of reducing sugars after 90 d at 10°C than did ‘mature’ bud tubers. Paper No. 878, Department of Vegetable Crops, Cornell University. This research was supported through HATCH project NYS161414, a contributing project to Regional Project NC150, and through HATCH project NYS161407.     

Effect of three anti-gibberellin growth retardants on tuberization of induced and non-induced Katahdin potato leaf-bud cuttings

Katahdin potato plants were grown in a growth chamber undernoninducing conditions and treated with three anti-gibberellin growth retardants. Other plants were sprayed with gibberellic acid and placed in aninducing growth chamber adjusted to promote tuber induction. Treatments were repeated the following week. After final treatment, apical, sub-apical, medial and basal leaf-bud cuttings were taken from each plant and placed in a mist chamber. After two weeks, cuttings were examined for tuberization. Two of the retardants were associated with approximately 3 and 2 fold increases in tuberization over the non-induced control. Although induced control cuttings exhibited almost complete tuberization, application of gibberellic acid to plants grown under identical conditions, reduced tuberization 14 fold. Tuberization response of induced control cuttings was unaffected by stem location. In non-induced control and quaternary ammonium compound-treated cuttings, basal cuttings tuberized significantly better than those taken from higher on the stem. This pattern was eliminated for plants treated with the triazole compound. Below-ground portions of donor plants were also examined and showed a significant increase in average rhizome number and total rhizome length associated with inducing conditions. Tuber number of donor plants was also increased for those plants grown under inducing conditions or treated with the triazole compound under noninducing conditions.     

Planting materials for warm tropic potato production: growth and yield of transplanted seedlings or rooted cuttings and tuber materials in the field

Expansion of potato production in lowland tropical regions has been constrained by the lack of planting materials, given that adapted genotypes and suitable field management practices now exist.

The respective performance of transplanted materials (i.e., true potato seed (TPS) seedlings or rooted stem cuttings) produced in situ in the warm tropics were compared with that of genetically identical seedling tubers (tubers produced from seedlings) or seed tubers. Seed and seedling tubers had been previously produced under optimal cool conditions. Transplanted materials achieved lower maximum leaf area index than did tuber materials (1.3–2.2 vs. 2.7) but relative growth rates of cuttings and seedlings were greater. This was in part due to the greater net assimilation rate of cuttings and to greater leaf:stem ratio for both compared with plants originating from tubers. Stolon and tuber formation were greater in seed tubers than in cuttings and in seedlings versus seedling tubers. On average, seedlings produced 14 tubers per plant, apical cuttings 12, seedling tubers 8, and stem cuttings 6.

Tuber yields within a genotype were statistically similar for crops from seed tubers or cuttings and for crops from seedling tubers or seedlings. However, the proportion of marketable (i.e., > 3.5 cm diameter) tubers was approximately 12% less in the crops from seed tuber and seedlings compared with those from cuttings and seedling tubers, respectively. Within a genotype, the crop duration in the field was similar whatever the type of planting material. Maximum yields, at 23 t/ha in warm sites, were still below those of temperate potato crops, but could be achieved equally well with transplanted in situ-produced materials or imported cool-climate seed tubers.     

Potato (Solanum spp.) production using apical cuttings and tuberlets under three contrasting environments of Vietnam

Potato production from rooted apical cuttings or from small tubers (l–20g) produced in high density beds has great potential in Asia. This is particularly important in non-traditional warmer environments. This research was conducted to assess the feasibility of producing many small tubers in high density beds. A second objective compared tubers from beds with transplanted rooted cuttings and traditional seed tubers for growth and yield in the field. Tuberlet production in beds exceeded 2000/m² with a density of 1000 plants/m² under optimal growing conditions while under high temperatures only about 1.25 tuberlets/plant were produced. In field experiments, transplanted cuttings yielded 20 t/ha in the mid and high elevation areas, only slightly less than tuberlets of 5–10g while at the hot site, yields were generally only 8 to 10 t/ha for both materials. Larger healthy seed tubers produced significantly higher yields at the low and high elevation sites. Tuberlets of 1–5g were also able to give yields of 20 t/ha in the mid-elevation site. These results indicate that cuttings and small tuberlets are two ways of growing potatoes which need to be further evaluated for socioeconomic assessment by farmers.     

Greenhouse production of potato (Solanum tuberosum L. cv. Désirée) seed tubers using in vitro plantlets and rooted cuttings in large propagation beds

Summary Seed tuber production fromin vitro potato plantlets and cuttings was conducted in large propagation beds in a greenhouse. Propagules of wholein vitro plantlets (WIP), plantlets with apical (ACR) and lateral (LCR) cuttings removed, the rooted apical cuttings (RAC) and rooted lateral cuttings (RLC) were planted at three densities of 25, 49 and 100 plants per m². The plantlets from which cuttings were removed (ACR and LCR) produced more tubers than the rooted cuttings (RAC and RLC); however, the most tubers were produced by WIP. RAC produced highest tuber yields followed by WIP and RLC. Intact WIP and plantlets with cuttings removed (ACR and LCR) produced twice as many tubers <40 g as those from rooted cuttings (RAC and RLC). The yield (kg/m²) as well as the number of tubers per m² increased with the increasing planting density within the densities tested.     

A promising method for screening drought tolerance in potato using apical cuttings

Ten diverse potato genotypes from apical cuttings were screened for drought tolerance in raised beds of 3:1 v/v volcanic soil:burnt rice hull medium. The object was to test whether this method could replace field evaluation. Growth analyses were done periodically on potatoes from apical cuttings grown in beds. Correlations were made with those from seed tubers concurrently grown in the field. Total and tuber dry matter yield of plants grown from apical cuttings in beds and from seed tubers in the field were significantly correlated (r=.80*). Drought stress sensitivity based on % reduction in tuber and total dry matter at maturity in beds was similar to the results found in the field at maturity. Consistency of the method necessitates the standardization of the age, quality and source of apical cuttings and the growing conditions particularly drought stress imposition.     

Production of above-ground seed tubers on stem cuttings from eight potato cultivars

Summary The formation of above-ground tubers on stem cuttings of eight potato cultivars was studied over three seasons. To promote tuber formation in the leaf axils, stems grown from single node cuttings were exposed to short day conditions. Tuber formation underground was reduced by covering the soil with a plastic sheet and by using single node cuttings planted with the leaf axils several centimetres above the soil surface. With all cultivars except Alpha, which produced mis-shapen tubers in all experiments, an average of 11 (maximum 40) tubers per cutting were harvested. Significant cultivar × year interactions were observed.     

Effects of auxin and calcium on phosphate partitioning in induced potato (Solanum tuberosum L.) cuttings

Summary Single-node leaf cuttings, from plants originated from apical cuttings on sprouted potato tubers (Solanum tuberosum L.), were used to study phosphate transport following hormone (IAA) and calcium treatments. Phosphate accumulation in tubers was significantly enhanced by axillary bud pretreatment with calcium followed by a subsequent treatment of the tuber formed with IAA. The results suggest that calcium may be necessary for the regulatory action of auxin on phosphate transport into the tuber.     

马铃薯早熟品种无病毒小薯的快速繁殖及良种繁育体系

自马铃薯极早熟品种东农303的无性系中筛选出未感染PSTV和PVX,PVY,PLRV的无性系东农303-1做为基础材科,采用茎尖脱毒产生476个单株系试管苗。再经酶联免疫和反向聚丙烯酰胺凝胶电源测定选出5个未感染X,Y,S,M,A,PLRV和PSTV的单株系做为生产无病毒小薯的原始材科。利用培养皿繁殖由瓶苗剪段扦插苗,并连续剪插顶腋芽快速生产无病毒小薯。在低温冷藏箱内(3～5℃)保存无病毒小薯,控制块茎休眠保证按时播种。在哈尔滨地区利用防虫温室生产无病毒小薯的最适时期为3～5月和9～11月。每年在防虫温室(240m~2)内可生产10万至15万个无病毒小薯。根据有翅桃蚜飞迁测报,采用保护地栽培可实现春秋两季栽培早熟品种的无病毒小薯生产原种的良种繁育体系。     

Field performance of potato shoot-tips proliferated in culture

Summary Plants of cvs Kennebec and Pontiac were propagated in petri dishes or flasks and rooted and transplanted into the field as cuttings. Plants from eight week old cuttings gave higher final yields than those from six-week-old cuttings. The field performance of Pontiac plants propagated in petri dishes was superior to that of plants propagated in flasks. Yields from cuttings were between 30% and 97% of those of plants from tubers.     

Field performance of potato (Solanum spp.) cuttings in the warm tropics: Influence of planting system,hilling, density and pruning

Growing potatoes from cuttings for seed and table potato production has great potential in Asia. There is limited information available explaining the agronomic methodology of growing cuttings in the field. This research was conducted to assess the importance of 4 management variables on the growth and tuber yield of cuttings. Three planting systems were evaluated with and without hilling. Only hilling significantly improved yields and increased tuber number per plant by 50%. Hilling also reduced tuber greening. Increasing plant population from 40,000 to 100,000 per hectare resulted in a yield increase of at least 50%, however average tuber size decreased. Pruning of the apical shoot at or after transplanting did not improve branching, canopy cover or tuber yield. Yields from cuttings were equal to or greater than the tuber seed grown control treatments. Yields ranged from 15 to 20 t/ha which is acceptable for the warm growing conditions. These results show the potential of using cuttings in commercial growing of potatoes in the warm tropics where tuber seed is difficult to obtain and maintain.     

脱毒马铃薯试管苗剪尖扦插无土繁殖研究

在防虫网室中无土扦插试管苗继代生产脱毒微型薯。用 4次剪尖和 4次培土办法 ,80d平均单株结薯数达 10 6个 ,110d单株商品粒数 >1g达 8 7个。增加剪尖和培土次数 ,是提高单株结薯数量的一种新技术方法     

Observations on systemic infection of potato plants grown from stem cuttings inoculated withCorynebacterium sepedonicum

Summary Potato stem cuttings dipped in high concentrations ofCorynebacterium sepedonicum developed into plants which showed ring rot symptoms on leaves, stems and tubers after 13 weeks. Stem cuttings dipped in very low concentrations of the bacterium developed into plants which visually could not be distinguished from non-infected plants, but latent infection was detected in leaves, stems and tubers.     

Effect of gibberellic acid and multiple harvests on production and reproductive value of seed potatoes produced above ground on stem cuttings

Summary Potato plants of cvs Eersteling and Bintje were grown from stem cuttings and induced to form aerial tubers for use as seed. Spraying the plants with gibberellic acid in concentrations of 10, 25 and 50 mg/l to induce stolon formation in the leaf axils led to a decrease in the number of tubers formed per plant. Multiple harvesting of the largest tubers from plants treated with gibberellic acid or not, approximately doubled the number of tubers formed but halved their individual weight compared with only one harvest at plant senescence. After a storage period of about 1 year, with their vigour declining, the aerial tubers were planted in the field. Aerial seed tubers taken from multiple harvests during the previous year produced the same number of tubers as plants grown from above-ground tubers harvested at plant senescence only, but the tuber yields declined with earlier harvesting when small (5–13 mm) aerial tubers were used, compared to larger (14–19 mm) tubers.     

Techniques for using sprouts for potato production in the tropics

A series of experiments were conducted in Vietnam to develop a system whereby detached sprouts from physiologically old green sprouted seed tubers could be used to grow potatoes. Three node segments from the mid or basal portion of the detached sprout produced the greatest percentage of shoots and roots. Growth was best in a medium of equal parts of sub-soil, pig manure and brick kiln ash. Sprout cuttings produced plantlets ready for transplanting in 14–20 days with mean daily temperatures of 22 to 24°C. When transplanted in mid-November, yields from sprout cuttings in field experiments were 10 to 18 t/ha which were 33% lower than from healthy seed tubers but more than the national average yield using degenerated seed tubers. Tubers produced by plants grown from sprout stored well and gave good yields when replanted the following year. Requests for reprints to International Potato Center, Box 933, Manila, Philippines.     

Observations on the bulking and development of tuber size distribution in maincrop potatoes at Rothamsted in 1964–75

Summary Tuber samples taken at 2-week intervals from plots of cvs King Edward, Majestic and Pentland Crown in 1964–75 showed that the maximum bulking rates ranged from 1 to 5 tonnes/hectare/week. Maximum tuber numbers were usually produced by 11 weeks after planting and thereafter numbers declined. In September, about 70% of the tubers initiated were recovered, and between 24 and 52% of the tubers had reached marketable size (>4 cm). Tuber size distributions developed similarly in all years with all cultivars. During tuber initiation the distributions appeared as one population, and usually between 9 and 11 weeks after planting a second population of larger tubers developed. The population of small tubers later declined although in most years it was still present in September. This development fitted a model based on a mixture of two normal distributions and was determined by five parameters; the proportion of tubers in the small population and the means and standard errors of both populations.     

Effect of two forms of maleic hydrazide on the cell structure at the midsection,stem and bud ends of the cortical and perimedullary regions of Russet Burbank tubers

The cortical and perimedullary cells of the potato tuber increased in size when treated with the diethanolamine and the potassium salt of maleic hydrazide. The best time for maleic hydrazide application appeared to be from mid to late July. There was a greater increase in cell size in the cortex than the perimedullary region and treatment with the amine salt was more effective than the potassium salt. The cells were smallest at the bud end; however, with maleic hydrazide treatment, increase in cell size was greater in this region compared to the midsection and stem end. From late August to late September the cell size of untreated tubers remained relatively unchanged, whereas, tubers treated with the amine salt showed a 16 to 46% increase with a lesser increase with the potassium salt. The rounder form of the treated tubers can be explained by the shape and increase in cell size in the cortical and perimedullary region. Increase in cell size also may help prevent the formation of misshapen tubers.     

2, 4-D Residues in tubers; Texture and respiration of potatoes in storage

Residues of 2, 4-D found in potato tubers ranged from 15 to 30 ppb at harvest when 2, 4-D was applied at the rate and time recommended for enhancement of color and control of tuber size. When used at higher rates and applied later, average residues reached 110 ppb. These residues did not include 2, 4-D bound to plant metabolites. In a single test, hydrolysis with aqueous acid resulted in a two to seven fold increase in 2, 4-D residues, suggesting a considerable portion of the 2, 4-D becomes combined with plant metabolites. Apparent respiration in storage of tubers from plants treated with 2, 4-D averaged 11% higher than tubers from plants not sprayed, but this was not great enough to be significant. Tubers of the same specific gravity from unsprayed plants and those sprayed with recommended rates of 2, 4-D were similar in texture.     

Parenchyma cell growth in potato tubers I. Different tuber regions

Enlargement rates of starch-storage parenchyma cells during growth of Kennebec and Russet Burbank potato cultivars were determined for cortical, perimedullary, and pith tissuues of bud ends, midsections, and stem ends of tubers. Average volumetric size of parenchyma cells increased 7 to 18x during growth of Russet Burbank tubers, with the greatest increases occurring in cortical and perimedullary cells of bud ends and midsections, and the least in stem ends and pith tissues. In Kennebec tubers parenchyma cells in both stem end and midsection increased only 5 to 8 x, whereas increases in bud ends ranged from 8 to 20 times. Cell enlargement to tuber enlargement ratios appproached unity early in growth of Russet Burbank tubers. As tubers increased beyond the 45 g size, cell enlargement and tuber enlargement rates were essentially equal. Calculations of cells per unit tissue volume agreed with ratio determinations. The timing of such unity appeared to be delayed in Kennebec tubers, and was not quite as pronounced as in Russet Burbank tubers. This may have been due to differences in growth rates of individual tubers in response to cultural conditions. In general, cells of harvestmature Kennebec tubers were about 60% as large as similar cells of Russet Burbank tubers.     

Auxin Modulates Gibberellin-Induced Effects on Growth,Yield, and Raw Product Recovery for Frozen Processing in Potato (<Emphasis Type="Italic">Solanum tuberosum</Emphasis> L.)

Tuber shape phenotype is an important determinant of raw product (≥7.6-cm-long French fries) recovery for frozen processing. Tuber length-to-width (L/W) ratios ≥1.8 translate to maximum yield of raw product; however, some cultivars produce tubers with much lower L/W ratios. While gibberellin (GA) can be used to elongate tubers, it also decreases tuber size and can thereby attenuate raw product recovery. We investigated the utility of GA and naphthaleneacetic acid (NAA) combination treatments for modifying tuber set, size, and shape to increase yield of raw product from ‘Payette Russet’ and ‘Alturas’; two late-season frozen-processing cultivars that often produce tubers with undesirably low L/W ratios. Models describing L/W ratio and fry yield by tuber size class were developed to translate total U.S. No. 1 tuber yields (>113 g) into yield of raw product. Increases in the L/W ratios of 113–284-g tubers had a greater effect on recovery of French fries (% fresh wt) than for tubers >284 g. Undersize (<113 g) and oversize (>340 g) tubers yielded 0 and 96% fries, respectively, regardless of L/W ratio. GA applied as a seed treatment effectively hastened emergence and altered tuber shape by increasing the L/W ratios of ‘Alturas’ and ‘Payette Russet’ tubers, enhancing total fry yield for the 113–340-g tubers by 24–46%, depending on concentration and application technique (dip, spray, in-furrow). However, GA also decreased apical dominance and shifted tuber size distribution away from >284-g tubers toward higher yields of <170-g tubers, erasing the gains in fry yield when all size classes (>113 g) were considered. When combined with GA, NAA maintained apical dominance, attenuated the shift in tuber size distribution, had no effect on the GA-induced increase in tuber L/W ratio, and only partly moderated the GA-induced stimulation of plant emergence. Raw product yield from ‘Payette Russet’ increased 12–39% in spray application trials by using NAA to confine the effect of GA to tuber shape and limit the loss of U.S. No. 1 tubers to undersize. Increases in tuber L/W ratio with GA/NAA seed treatments translated to increased yield of fries only when the relative concentrations were adjusted to minimize loss of >284-g tubers and gain in undersize tubers, as dictated by cultivar sensitivity to GA. ‘Alturas’ was less sensitive to GA than ‘Payette Russet’ for shifts in tuber size distribution but not shape, resulting in 17% increase in raw product with GA alone in pre-plant seed spray application studies. GA/NAA combination treatments provide an effective approach to manipulate tuber size distribution and enhance the yield of raw product for frozen processing in cultivars with a rounder tuber shape phenotype.