Analyzing genotype by environment interaction in potato using yield-stability index

The plant breeding program of the National University of Colombia carried out 10 potato regional trials during 1998 and 1999 to evaluate 15 promising potato clones (Solanum tuberosum ssp.andigena). Genotype by environment interaction was analyzed using Kang’s methodology, which links yield performance and phenotypic stability. A MACRO was implemented using the SAS system to obtain yield-stability indices. Shukla’s variance was estimated by restricted maximum likelihood (REML), which allowed handling unbalanced data for both genotypes and replicates. In addition, a multivariate analysis methodology was developed, based on the yield-stability index. This methodology is useful when tuber yield is categorized by size and quality, which is usual in Colombian potato harvests.     

Influence of applied nitrogen on potato part I: Yield,quality, and Nitrogen uptake

Fertilizer nitrogen (N) may be managed to increase crop production and profitability while reducing nitrate contamination of groundwater. A two-year field investigation was conducted to evaluate the effects of applied N on tuber yield and quality, dry matter production and N uptake of potato (Solanum tuberosum L. var. Russet Burbank) grown on irrigated sandy soils in Michigan. Nitrogen was applied as ammonium sulfate [(NH₄)₂SO₄] at rates of 0, 56 and 112, kg N ha^?1 in a single application at planting or 112 and 168 kg N ha^?1 in split applications during the growing season. Total tuber yield generally increased with N applications up to 112 kg N ha^?1. Only one of the three experimental sites showed an increase in marketable tuber yield when 112 kg N ha^?1 was split evenly between planting and tuber initiation. Tuber specific gravity was not affected by N rate. Nitrogen rates of 112–168 kg N ha^?1 maximized dry matter production and plant tissue N concentration at onset of maturity and harvest. Tuber N concentration at harvest ranged from 13–17 g kg^?1 at two of the three locations. Values for the third experiment were 10–13 g N kg^?1. Whole crop N uptake at onset of senescence ranged from 45 to 225 kg N ha^?1 across all locations and treatments. An average of 67 percent of this N was found in tubers at harvest. Nitrogen fertilization exceeded N removal in harvested tubers by more than 50 kg N ha^?1 only for the 168 kg N ha^?1 treatment. These results indicate that acceptable tuber yield can be obtained with lower N rates than those currently used by most producers, with the potential for reducing net loss of N from the soil.     

Performance of populations derived by selecting for resistance to potato leafhopper in A 4XSolanum Tuberosum X 2XSolanum Chacoense cross

Intercross and backcross populations derived from aSolanum tuberosum L. (2n = 2x = 48) ×Solanum chacoense Bitt. (2n = 2x = 48) cross by selecting for resistance to potato leafhopper (PLH) (Empoasca fabae Harris), were tested in the field. In F2 and F4 populations, the levels of nymphal infestation and leaf necrosis from PLH feeding were considerably lower and tuber yields were much lower compared with those measured on the susceptible cultivar Kennebec. No differences were found between the two populations. Backcrosses of the F2 and F4 populations toS. tuberosum decreased resistance to PLH. Resistance to infestation was still greater than that of Kennebec; severity of leaf necrosis equaled that of Kennebec. Tuber yields increased, but were less than Kennebec’s yield. Foliage types shifted closer to those ofS. tuberosum. Three generations of selection and intercrossing within the backcross populations did not change the level of resistance to PLH but did tend to lower tuber yields. Foliage types remained primarilyS. tuberosum in appearance although distinctive types segregated with increased frequency. A second backcross toS. tuberosum did not change the level of resistance to PLH or the level of tuber yield relative to those of the first backcross or Kennebec.     

Influence of temperature and length of storage on resistance of potato to tuber rot induced byErwinia chrysanthemi

Tubers of 11 clones ofSolanum tuberosum subsp.andigena (andigena) and 12 cultivars ofS. tuberosum subsp.tuberosum (tuberosum) were inoculated with water suspensions (5.5 × 10⁴ 5.5 × 10⁵, 5.5 × 10⁶ CFU/ml) ofErwinia chrysanthemi. Tubers were inoculated immediately after harvest and after 6 and 16 wk of storage at 4 and 23°C. Tuber rot incidence in andigena and tuberosum increased as inoculum concentration increased. Based on tuber rot severity, clones of andigena were classified as resistant, intermediate, or susceptible and cultivars of tuberosum were classified as intermediate or susceptible. Rot severity increased in all tubers stored at 4°C and in tubers of tuberosum stored at 23°C; rot did not increase in tubers of andigena stored at 23°C. Electrolyte leakage (EL), total sugars (TS), reducing sugars (RS), non-reducing sugars (NRS) and dry matter (DM) were determined in non-inoculated tubers. There was a significant positive correlation between the rate of EL, concentration of RS and tuber rot in andigena and tuberosum. Tuber rot and DM were negatively correlated in tubers of andigena; but they were not correlated in tuberosum. Clones of andigena with low EL, TS, RS, and high DM were resistant to tuber rot, and the incidence of tuber rot in these clones was much less influenced by temperature and length of storage. The influence of temperature and length of storage on susceptibility toE. chrysanthemi may be explained by increased cell membrane permeability; increased leakage of accumulated sugars in potatoes stored at 4°C could favor bacterial proliferation resulting in more disease.     

Effect of soil salinity on internal browning of potato tuber tissue in two soil types

A study was carried out with potato (Solanum tuberosum; cv. Atlantic) during 2001 and 2002 to determine the effect of soil salinity on internal tuber browning. The effect of varying levels of soil salinity on proline content, polyphenol oxidase enzyme activity, and chlorogenic acid content in potato leaves and tubers was examined. NaCl treatments (2.1, 4.25, 6.38, 8.5 g NaCl L^?1) were applied to the pots, the first 46 days after planting, and four additional treatments were applied, each about 7 days apart. Increasing NaCl concentrations resulted in an increase in browning of tuber tissue and proline content in the tubers. Chlorogenic acid content in the leaves increased up to 6.4 g NaCl L^?1, but then decreased at 8.5 g NaCl L^?1 and in tubers tended to be maximal at the highest saline concentration tested (8.5 g NaCl L^?1). Increasing NaCl concentration resulted in a reduction in yield per plant and average tuber weight, and also increased tuber number. There were major differences in the impact of salinity over the 2-year period, which was probably due to the impact of the growing media; a low organic matter (about 1% OM) silty loam soil and a high organic content (about 90% OM) Muck soil were used in 2001 and 2002, respectively. Tuber browning increased linearly with salinity in 2002, but only markedly increased at 8.5 g NaCl L^?1 in 2001. Sodium and chloride ion concentration was always greater (about two times) at equivalent application rates in the 2002 trial. The high organic matter content soil retained sodium and chloride ions more effectively than the silty loam soil and enhanced the impact of increased salinity concentration on physiological properties of potato plants and particularly on tuber tissue browning and proline accumulation.     

Selection of Yield-Associated Morphological and Biochemical Traits Using Correlation and Path Coefficient Analysis in Potato (<Emphasis Type="Italic">Solanum tuberosum</Emphasis> L.) in the Foothills of North-Western Himalayas

The objective of the study was to assess the direct and indirect effects of 13 important morphological and biochemical traits on yield enhancement in 28 advanced breeding lines of potato (Solanum tuberosum L.) in the foothills of north-western Himalayas. Tuber yield was positively correlated with number of tubers per plant (r?=?0.76), number of stems per plant (r?=?0.53), number of leaves per plant (r?=?0.43) and tuber weight (r?=?0.37). Furthermore, tuber yield exhibited a significant negative correlation with days to maturity (r?=???0.39). Days to 50% emergence had a significant negative correlation with protein content (r?=???0.42). Path analysis revealed that the components of yield, number of tubers per plant and tuber weight, had high positive direct effects (0.876 and 0.618, respectively) on tuber yield, whereas the effects of other traits were low (≤?0.128). Furthermore, tuber weight had an indirect negative effect on tuber yield through the number of tubers. Tuber size had a low correlation (0.19) with tuber yield because a positive indirect effect (0.451) through tuber weight was balanced by a negative indirect effect (??0.254) through tuber number. The number of stems and number of leaves had positive indirect effects (0.377 and 0.377, respectively) on tuber yield through tuber numbers, whereas days to maturity had a negative indirect effect (??0.298) through tuber numbers. There were virtually no indirect effects through the biochemical traits. The implications for potato breeding are discussed.     

Reaction ofSolanum tuberosum andSolanum species toMeloidogyne hapla

The reactions of 218 clones ofSolanum tuberosum and 238 accessions of 55 tuber-bearingSolanum species toMeloidogyne hapla were determined by planting them in soil naturally infested withM. hapla and the microsclerotial form ofVerticillium alboatrum. Degree of root galling was rated from none (0) to severe (5). Incidence of root galling on clones was slight as evidenced by ratings of 0, 0.5 and 1.0 for 38, 32 and 18 percent of them, respectively. As incidence of root galling increased there was a tendency for percentage of galled tubers and internal tuber infection byM. hapla to increase. Of many family progenies ofS. tuberosum tested, those from family B7147 (Penobscot x W39-1) were the most resistant toM. hapla. Incidence ofM. hapla root galls andVerticillium alboatrum wilt symptoms onS. tuberosum clones indicated there was no apparent interaction between these two pathogens. Eighty-one percent of the 238 accessions remained free from root galls.Solanum species free from root galls and represented by three or more accessions werebrachycarpum, bulbocastanum, cardiophyllum, hjertingii, hougasii, infundibuliforme, kurtzianum, martinasense, multidissectum, multiinterruptum, papita, sparsipilum, spegazzinii, stoloniferum, tarijense, andvernei. S. microdentum (PI320312) andS. tuberosum ssp.andigena (PI245926) had the most extensive root systems free ofM. hapla galls.     

Management of plant residue for cassava (Manihot esculenta) production on an acid Ultisol in Southeastern Nigeria

A study consisting of two experiments was conducted in southeastern Nigeria during 1983 and 1984 to determine whether cassava (Manihot esculenta Crantz) production on sandy, acid Ultisols could be improved by residue management techniques. One experiment studied the effect of location of Eupatorium odoratum mulch on soil properties and crop growth. A second experiment studied the effect of tillage system and Eupatorium odoratum mulch on soil properties and crop growth. In both experiments mulch was applied at an annual rate of 12 t¹ ha⁻¹ (25% moisture content) in a split application at planting and 150 days after planting (DAP). No fertilizer was applied during the experiment.Concentration of mulch in the plant row resulted in values of within-row bulk density in the surface 0.10 m which were lower by 15% and 13% in 1983 and 1984, respectively. Tillage in combination with mulch reduced bulk density in the surface 0.10 m by an average of 10% and 9% in 1983 and 1984, respectively. No significant differences were found among other treatments. Soil chemical properties were unaffected by treatments in both experiments. Cassava tuber yield was unaffected by location of Eupatorium odoratum mulch. Both plowing and no-tillage when combined with mulch improved tuber yields. Cassava tuber yields of untilled plots were 16.8 and 12.7 t ha⁻¹ during 1983–1984, and 13.1 and 8.3 t ha⁻¹ during 1984–1985 in mulched and unmulched treatments, respectively. Tuber yields of tilled plots were 14.5 and 13.1 t ha⁻¹ during 1983–1984, and 11.3 and 6.9 t ha⁻¹ during 1984–1985 in mulched and unmulched treatments, respectively.     

Effect of random mating on yield and specific gravity in twoSolanum tuberosum subsp.tuberosum populations

A group of biparental crosses of breeding clones and varieties (Solanum tuberosum subsp.tuberosum) from the USDA potato breeding program, Beltsville, MD, was used to establish two randomly mated populations. Random mating without selection was continued for seven generations, then cycles 1, 3, 5, and 7 were tested for yield and specific gravity. There was a small but non-significant decrease in tuber weight per hill, and a small but non-significant increase in tuber number from cycle 1 to cycle 7. Mean tuber weight significantly (P < 0.01) decreased (12%) from cycle 1 to cycle 7. Specific gravity also significantly (P < 0.10) decreased over cycles. The variance of clones within cycles did not significantly change over cycles for any of the traits measured.     

Cytoplasmic evaluations during substitution backcrossing inSolanum

Summary Sterility-resistant cytoplasmic factors ofSolanum tuberosum spp.andigena (Juz. & Buk.) Hawkes and ofSolanum phureja (Juz. & Buk.) were combined with chromosomal genes ofS. tuberosum ssp.tuberosum. Eleven morphological characters of reciprocal F₁ and BC₁ progenies were monitored to evaluate rate of progression towards characteristics occurring in the recurrent ssp.tuberosum parent. Female and male fertilities of F₁ and BC₁ populations were also evaluated. Cytoplasmic factors did not influence morphological parameters consistently, except those relating directly to fertility. Differences between reciprocal progeny depended more upon the genes of individual parents used in crosses than on cytoplasm source. No consistent reciprocal differences occurred in tuber characters and those differences which arose seem to reflect a maternal rather than a cytoplasmic influence. F₁ and BC₁ progenies containing the sterility-resistant cytoplasmic factors of ssp.andigena or ofS. phureja had higher fertility than their respective reciprocal progenies with cytoplasm of ssp.tuberosum. Pennsylvania Agricultural Experiment Station Journal Series No 6212.     

Calcium and potassium fertilization of potatoes grown in North Florida I. Effects on potato yield and tissue Ca and K concentrations

Potatoes (Solanum tuberosum L.) were grown during 3 seasons on an Ellzey fine sandy soil to evaluate the effects of Ca and K rate, Ca placement, and cultivar on tuber yield and Ca and K concentration. Mehlich I soil extractable Ca concentration ranged from 436 to 860 mg·kg^t-1. Application of Ca at 0, 450 and 900 kg·ha^t-1 from gypsum increased soil Ca in each season, petiole Ca in 2 of 3 seasons, and tuber medulla and periderm Ca concentrations in one of three seasons. Tuber yields were increased from 29.8 to 31.6 t·ha^t-1 with an increase from 0 to 450 kg Ca·ha^t-1 in one of three seasons. Tuber specific gravity was not affected by Ca rate. With an increase in application of K from 225 to 450 kg·ha^t-1, Ca concentrations were decreased in the petiole and medulla in 2 of 3 seasons and in the periderm in 1 of 3 seasons. Petiole, medulla, and periderm K concentrations were increased in 2 of 3 seasons with an increase in K rate. Yields were not affected by K rate, but specific gravities of tubers were lower in 2 of 3 seasons with an increase in K rate. Broadcast placement of Ca resulted in higher petiole, medulla, and periderm Ca and higher tuber yields in 1 of 2 seasons than with band placement (the placement effect on yield occurred in the season that placement had no effect on tissue Ca). Periderm tissue of Superior was higher in Ca than that of La Chipper, and petiole tissues of Atlantic were higher than that of Superior, but medulla tissue in 1 of 2 seasons was higher in Ca with Superior than Atlantic. Tuber yields and specific gravities were higher with La Chipper and Atlantic than with Superior.     

Potato planter performance and effects of non-uniform spacing

A survey of potato (Solanum tuberosum L.) plant stands in upstate New York over a three-year period showed that the average distance between plants was 4 cm wider than intended. Plant stands averaged 83%. The failure to plant seed pieces was the major reason for missing hills. Seed rot was not generally a problem, although one field in the survey was severely affected. Speed of planting up to 6.7 km/h had no consistent effect on average spacing or uniformity of seed piece distribution. Seed type (whole or cut) and mechanical condition of planter influenced spacing. Experiments conducted over four years indicated that the non-uniform seed piece distribution delivered by commercial picker-arm planters does not adversely affect crop yield or tuber size. Non-uniform seed distribution with extremely high coefficients of variation (greater than 100%), however, affected yield, tuber size and tuber number. Tuber numbers and yields were decreased by reducing the number of seed pieces planted per unit area whether or not the pieces were uniformly spaced.     

Glycoalkaloid content in tubers of hybrid and backcross populations from aSolanum tuberosumx s. chacoense cross

The glycoalkaloid contents of tubers were measured in hybrid and back-cross populations derived from a cross ofSolarium chacoense Bitter (PI 472810, 2n=2x=24) withSolanum tuberosum L. (2n=4x=48). In tubers sampled from near the median size in each population and parent, the mean total glycoalkaloid (TGA) contents of theS. chacoense andS. tuberosum parent genotypes, and the F₂ and F₄ hybrid genotypes were 245, 4, 39, and 35 mg/ 100 g fresh weight (fw), respectively. Backcrossing the F₂ genotypes toS. tuberosum reduced the mean TGA content to 15 mg/100 g fw. A second backcross further reduced the content to 9 mg/100 g fw. However, some genotypes in both backcross populations (25% and 10%) had TGA contents above the generally accepted upper limit of 20 mg/100 g fw. Tuber size was significantly smaller in theS. chacoense parent and the hybrid populations compared with the size in theS. tuberosum parent and backcross populations. In a second sampling of tubers from each population, intentionally selected to equalize tuber size among populations, the mean tuber size for populations was reduced by 79%. The mean population TGA content increased by 44%. However, the differences and rankings among parent, hybrid, and backcross populations were the same for both tuber samplings.     

Characterization of forty-four potato varieties for resistance to common scab,black scurf and silver scurf

Common scab, black scurf and silver scurf belong to serious diseases of cultivated potato that especially impair tuber quality. Tuber infection in 44 potato (Solanum tuberosum ssp. tuberosum L.) varieties was evaluated using two measures – severity and incidence of infected tubers. Both measures were highly correlated. An important result derived from this study supports fungicide application against potato late blight secondarily acts on reducing tuber infection by all evaluated pathogens. Therefore, the conventional potato growing seems to be more effective compared to ecological growing. The pedigree analysis of 44 varieties indicated the presence of Solanum demissum genotypes in the variety genome may negatively affect variety response to Helminthosporium solani presence.     

Effects of cement kiln dust on soil and potato crop quality

Cement kiln dust is a potential source of K and Ca for crops on acidic soils in Eastern Canada. The objective of this study was to assess the effect of cement kiln dust on soil chemical properties and potato (Solanum tuberosum L. cv. Superior) yield and quality on two Spodosols. Four rates of cement kiln dust, commercial K fertilizers, and lime were yearly applied and arranged in a randomized complete block design with four replicates. Soil extractable K and Ca increased rapidly after cement kiln dust applications and were comparable to commercial fertilizers or lime treatments. Heavy metal soil contents and plant uptake were not influenced by treatments. Soil metal contents decreased from to initial soil levels and were lower than recommended maximal norms. Tuber yields increased with rates of cement kiln dust and commercial fertilizers but decreased with lime rates. Yields were positively correlated to soil extractable K and partially with extractable Mg. The K and Mg plant uptake increased with cement kiln dust and commercial fertilizers rates but was significantly reduced by liming. Tuber specific gravity decreased with the highest commercial fertilizers and cement kiln dust rates. These results showed that cement kiln dust is an effective source of K and Ca for potato production without short term loss in tuber quality or soil contamination by metals.     

Tolerance to potato leafhopper inSolanum tuberosum L. gp. Tuberosum clones

We identified clones inSolanum tuberosum L. gp. Tuberosum breeding populations that, although susceptible to infestation by potato leafhopper,Empoasca fabae (Harris), exhibited a tolerance which was manifested by the ability to produce higher than expected tuber yields when heavily infested with leafhoppers. Such tolerance was noted in a number of clones in varying degrees, but one, B6930-1, was exceptional. It sustained only a 19% loss in tuber yield compared to ‘Katahdin,’ a susceptible cultivar, that averaged 33% lower tuber yields under similar infestation levels. We studied the seasonal growth patterns of this clone and compared them to those of Katahdin, and B6705-10, a breeding clone with known resistance to leafhopper infestation. We found that much of B6930-l’s tolerance results from its early, vigorous vine growth and its early and rapid rate of tuber bulking, enabling this clone to escape some of the effects of leafhopper feeding, whereas Katahdin was usually just beginning to tuberize at the height of leafhopper infestation.     

Cytoplasmic substitution inSolanum. II. Tuber characteristics of reciprocal backcross progeny

Summary Recurrent backcrosses (BC) were used to introduce nuclear factors ofS. tuberosum L. ssp.tuberosum into the cytoplasm of Andean potatoesS. tuberosum ssp.andigena (Juz. and Buk.) Hawkes andS. phureja Juz. and Buk. Each generation BC was produced in reciprocal directions to test the effect of cytoplasmic substitution on yield. This report analyses tuber number, tuber weight, and tuber length of BC₂ and BC₃ substitution into ssp.andigena cytoplasm and BC₂ and BC₂ substitutions intoS. phureja cytoplasm. Direction of cross had no consistent significant effect on yield components of ssp.andigena substitution lines. InS. phureja reciprocal progenies direction of cross was responsible for significant differences of some reciprocal sets. When there were significant differences the higher yield usually occurred when ssp.tuberosum was the pistillate parent, but in some progenies when ssp.tuberosum was the pistillate parent the yield was significantly lower than in the reciprocals. It is suggested that differences between reciprocals resulted from chromosomally encoded gene action, resulting from maternal and/or paternal effects, rather than cytoplasmic factors. Authorized for publication as paper No. 7494 in the Journal Series of The Pennsylvania Agriculture Experiment Station.     

Screening for gibberellin deficiency mutants inSolanum tuberosum ssp.andigena

A GA deficiency mutant was previously described in a single population ofSolanum tuberosum ssp.andigena (adg). A representative sample of 120 adg populations in the US Potato Genebank was screened for the dwarfing mutant. Up to 500 seedlings of each adg population were evaluated. Dwarfs were detected in 14 populations from a minimum of 0.2% to a maximum of 27.7%, indicating that the allele is not particularly rare or at risk of loss from the Genebank.     

Reaction of some wild and cultivated potato varieties to charcoal rot

With a view to select potato varieties possessing resistance to charcoal rot, laboratory tests were carried out at the Central Potato Research Institute, Simla (India). Five hundred and twenty six clones comprising tuber-bearing species ofSolanum and varieties and hybrids of potato were screened for their reaction toMacrophomina phaseoli (Maubl.) Ashby. A high degree of resistance was observed in six clones ofSolanum chacoense and four hybrids withS. chacoense germ plasm, while moderate susceptibility was observed in another six clones ofS. chacoense, three clones ofSolanum tuberosum ssp.andigena and nineteen hybrids produced at the Institute.