General and specific combining ability studies of yield and yield character of sweet potato weevil in predominant and non-predominant environments

2021 ◽  
Vol 20 (1) ◽  
pp. 8-16
Author(s):  
M.S. Afolabi ◽  
G.O. Agbowuro ◽  
A.E. Salami ◽  
M.O. Akoroda

Combining ability for marketable sweet potato root yield were carried out using ten sweet potato varieties and their F1 hybrids in Cylasformicarius endemic (Landmark University, Omu Aran) and free (University of Ibadan) environments during 2012 cropping season. Both general combining ability and specific combining ability play significant role on traits such as marketable root yield, non- marketable root yield, and total number of storage root/plant and marketable storage root, root size, percentage of tuber damage and weight of total roots, as well as the incidence and severity were generally low, suggesting the role of additive and dominant gene action in tolerances to Cylasformicarius. Hybrids from the parents Resisto, TIS 87/0087 displayed high performance in term of Cylasformicarius tolerance. These parents and their hybrids appeared to have gene pools for Cylasformicarius tolerance that can be manipulated for developing promising hybrids in South west, Nigeria.

Author(s):  
M. S. Afolabi ◽  
M. O. Akoroda

Introduction: Combining ability studies in sweetpotato marketable root yield were carried out using ten sweetpotato varieties and their F1 hybrids in Cylas formicarius endemic (Omu Aran) and free (Ibadan) environments during 2012 cropping season. Study Design: The genetic material used for this experiment was from the germplasm                collection of the Department of Agronomy, University of Ibadan, Nigeria. This material               comprised of 10 varieties of sweetpotato: 5 orange fleshed, 3 white fleshed and 2 yellow             fleshed. Place and Duration of Study: The field trial was carried out in C. formicarius endemic (Omu Aran) and Non-endemic (Ibadan) environments both in South West Nigeria during the raining season of 2012. Methods: Collected data were subjected to diallel analysis using Griffing (15) approach in method I (parents, crosses reciprocals together), Model I (fixed effects). Both general combining ability (GCA) and specific combining abilities (SCA) were computed using PBTools, version 1.4. for the 10 parents and their F1 hybrids with respect to C. formicarius. Results and Discussion: The result obtained from this study showed that some parents were tolerant to C. formicarius, but level of tolerance varied probably due to differences in genetic background among the parental population or time of planting. Hybrids from the parents resisto, TIS 87/0087 displayed high performance in term of C. formicarius tolerance. These parents and their hybrids appeared to have gene pools for C. formicarius tolerance that can be manipulated and used to develop promising hybrids in South west, Nigeria.  


2021 ◽  
Vol 22 (9) ◽  
pp. 4826
Author(s):  
Yang Gao ◽  
Zhonghou Tang ◽  
Houqiang Xia ◽  
Minfei Sheng ◽  
Ming Liu ◽  
...  

A field experiment was established to study sweet potato growth, starch dynamic accumulation, key enzymes and gene transcription in the sucrose-to-starch conversion and their relationships under six K2O rates using Ningzishu 1 (sensitive to low-K) and Xushu 32 (tolerant to low-K). The results indicated that K application significantly improved the biomass accumulation of plant and storage root, although treatments at high levels of K, i.e., 300–375 kg K2O ha−1, significantly decreased plant biomass and storage root yield. Compared with the no-K treatment, K application enhanced the biomass accumulation of plant and storage root by 3–47% and 13–45%, respectively, through promoting the biomass accumulation rate. Additionally, K application also enhanced the photosynthetic capacity of sweet potato. In this study, low stomatal conductance and net photosynthetic rate (Pn) accompanied with decreased intercellular CO2 concentration were observed in the no-K treatment at 35 DAT, indicating that Pn was reduced mainly due to stomatal limitation; at 55 DAT, reduced Pn in the no-K treatment was caused by non-stomatal factors. Compared with the no-K treatment, the content of sucrose, amylose and amylopectin decreased by 9–34%, 9–23% and 6–19%, respectively, but starch accumulation increased by 11–21% under K supply. The activities of sucrose synthetase (SuSy), adenosine-diphosphate-glucose pyrophosphorylase (AGPase), starch synthase (SSS) and the transcription of Susy, AGP, SSS34 and SSS67 were enhanced by K application and had positive relationships with starch accumulation. Therefore, K application promoted starch accumulation and storage root yield through regulating the activities and genes transcription of SuSy, AGPase and SSS in the sucrose-to-starch conversion.


2018 ◽  
Vol 3 (1) ◽  
pp. 644-651
Author(s):  
A.O. Adekiya ◽  
C.M. Aboyeji ◽  
T.M. Agbede ◽  
O. Dunsin ◽  
O.T.V. Adebiyi

Abstract Micro-nutrients especially zinc can not only increase the yield of sweet potato but can also improve the quality of tubers. Hence, experiments were carried out in 2015 and 2016 cropping seasons to determine the impact of various levels of ZnSO4 fertilizer on soil chemical properties, foliage and storage root yields and proximate qualities of sweet potato (Ipomoea batatas L.). The experiments consisted of 5 levels (0, 5, 10, 15 and 20 kg ha-1) of ZnSO4 fertilizer. These were arranged in a randomized complete block design and replicated three times. ZnSO4 increased (with the exception of P) soil chemical properties compared with the control. N, K, Ca, Mg and Zn were increased up to the 20 kg ha-1 ZnSO4 level in both years. ZnSO4 reduced P concentrations in soil as the level increased. For sweet potato performance, 5 kg ha-1 ZnSO4 fertilizer had the highest values of foliage yield (vine length and vine weight) and storage root yield. Using the mean of the two years and compared with the control, ZnSO4 fertilizer at 5 kg ha-1 increased storage root yield of sweet potato by 17.4%. On fitting the mean storage root yield data of the two years with a cubic equation, the optimum rate of Zn for sweet potato was found to be 3.9 kg ha-1 to achieve the maximum sweet potato yield. In this study, relative to the control, ZnSO4 fertilizer increased moisture and decreased the fibre contents of sweet potato. There were no consistent patterns of variation between the 5, 10, 15 and 20 kg ha-1 ZnSO4 treatments for proximate qualities except that the highest values of fat, protein, carbohydrate and ash was at 5 kg ha-1 ZnSO4.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Josabeth Navarro ◽  
Jahdiel Salazar ◽  
James Jihoon Kang ◽  
Jason Parsons ◽  
Chu-Lin Cheng ◽  
...  

South Texas is located in a subtropical semiarid climate, and due to high temperature and irregular precipitation, farmers opt to leave their fields fallow during the summer months jeopardizing overall soil health. We evaluated whether sweet potato (Ipomoea batatas) cultivation coupled with drip irrigation could restore soil biological activities compared with bare fallow. Additionally, because sweet potatoes have high demand of soil nutrients, especially potassium (K), we evaluated the nutrient supply of locally sourced soil amendments. Sweet potato was cultivated during summer 2018 in McAllen, Texas, under control (no fertilizer), NPK (synthetic fertilizer), RC (yard-waste compost), and AC (compost produced under an enhanced composting process), and biochar (gasified walnut shell at 900°C), each with three replicates. Soil amendments were applied at different amounts to result in a rate of 80 kg K ha−1. Soil biological indicators were microbial biomass phosphorous, phosphatase activity, and the rate of fluorescein diacetate hydrolysis (FDA). Available nitrogen, phosphorus, potassium, and sodium were also quantified. Aboveground biomass and storage root yield estimated sweet potato’s agronomic performance. Cultivation and irrigation stimulated soil enzyme activities and microbial biomass-phosphorous. Sweet potato yields were the highest in NPK treatment but still 2.8 times lower than variety’s potential yield. Storage root yield was inversely related to aboveground biomass, suggesting that growing conditions benefited the production of shoot versus roots. Both biochar and AC treatments stimulated FDA rates and K availability. Soil pH and sodium concentration increased in all treatments over the growing season, possibly due to river-sourced irrigation water. Together, these findings show that crop cultivation promoted soil biological activities and the maintenance of nutrient cycling, compared to bare-fallow conditions. For a better agronomic performance of sweet potato, it would be necessary to identify management practices that minimize increase in soil pH and salinity.


2020 ◽  
Vol 35 (2) ◽  
pp. 289
Author(s):  
Edyson Indawan ◽  
Sri Umi Lestari ◽  
Nurita Thiasari ◽  
Pramono Sasongko

Sweet potato is a dual-purpose crop, which could produce both food and feed. The vine pruning prior to storage root harvesting was intended to increase the quantity and quality of fresh forage for animal feed. This study aims to evaluate whether periodic pruning can affect the storage root yield and its starch content. This experiment employed split-plot design with two factors and three replications. The first factor as main plot was vine pruning which consisted of four distinct pruning times (four times, three times, twice and once). The second factor as sub-plot was cultivars which consisted of six dual-purpose cultivars and two controls. The storage root yields, vine yields, starch yields and the reduction in storage root yields were observed. The results showed that the vine pruning decreased the storage root yields, with small increases the vine yields. The percentage of the reduction in storage root yields were 4-58%, while the decrease vine yields are relatively inconsistent. The starch yield of the cultivars with one pruning time were in the range of 2.34-6.67 ton ha<sup>-1</sup>. On the contrary, the three times pruning or more since 80 days after transplanted can reduce the starch yields for more than 50%. The slight increase in vines yield due to pruning was followed by the decrease in storage root yields and starch content of the sweet potato.


2016 ◽  
Vol 8 (2) ◽  
pp. 999-1005
Author(s):  
Rajni Tiwari ◽  
Dinesh Kumar Singh

The present investigation was undertaken to investigate the extent of heterosis and combining ability on earliness, vegetative traits and yield of Cucumber. A field experiment was designed in line x tester mating design with 11 parents (including 8 parthenocarpic lines namely Pant parthenocarpic cucumber-2, Pant parthenocarpic cucumber-3, Nun-3139, Nun-3121, Nun-3141, Infifnity, Isatis, Kian, and 3 monoecious testers namely PCUC-8, PCUC-15, Pant Kheera -1 {also known as PCUC-28}) and their 24 F1 hybrids to work out the heterosis and combining ability for earliness and yield characters. All traits pertinent to earliness and yield showed significant values for heterosis and combining ability. Appreciable heterosis in desirable direction was found over better parent and check parent by the cross PCUCP-3 x PCUC-15 for earliness characters viz. days to first female flower (-71.18 & -70.31), days to first harvest (-3.40 & -22.01) whereas Cross Kian x PCUC-15 showed maximum number of fruits per plant (8.36 & 106.35) and fruit yield (86.34 & 210.74 respectively). The crosses PCUCP-3 x PCUC-15 and Nun-3139 x PCUC-8 showed significant specific combining ability for earliness and yield characters. Cross Nun-3139 x PCUC-8 showed significant yield regarding heterosis and SCA. Regarding general combining ability for earliness parent Isatis and for yield characters parent Kian stood in top. Cross Nun-3139 x PCUC-8 showed Maximum specific combining ability for node number to first female flower (-0.98), number of fruits per plant (3.39) and fruit yield (220.57).


HortScience ◽  
2018 ◽  
Vol 53 (2) ◽  
pp. 167-175 ◽  
Author(s):  
Fekadu Gurmu ◽  
Shimelis Hussein ◽  
Mark Laing

Orange-fleshed sweetpotato (OFSP) is an effective, low-priced, and sustainable source of β-carotene (provitamin A). However, most OFSP varieties have low storage root dry matter content (DMC), which influences their acceptance by small-scale farmers and hence needs to be improved. The objective of the study was to determine the combining ability, type of gene action, heterosis and heritability of storage root DMC, β-carotene content, and yield-related traits of selected sweetpotato clones for further evaluation and breeding. Crosses were conducted using a 7 × 7 half-diallel mating design and a total of 28 genotypes (seven parents and 21 crosses) were evaluated at four locations in Ethiopia using a 7 × 4 alpha lattice design with two replications. The performance of the genotypes was significantly different (P < 0.01) across the four locations for storage root DMC, β-carotene content, sweetpotato virus disease (SPVD) reaction, storage root yield, and harvest index (HI). The general combining ability (GCA) and specific combining ability (SCA) mean squares were significant (P < 0.01) for all traits except the SCA effect of storage root DMC. The GCA to SCA variance ratios were 0.96, 0.94, 0.74, 0.96, and 0.97 for storage root DMC, β-carotene content, SPVD, fresh storage root yield, and HI, respectively, indicating that the inheritance of these traits was controlled mainly by additive genes. Progenies of crosses involving Ukerewe × Ejumula, Ukerewe × Pipi, Resisto × Pipi, and Ejumula × Pipi exhibited high levels of positive heterosis for storage root DMC. Similarly, progenies of crosses including Resisto × Pipi and Resisto × Ogansagan had higher positive heterosis for fresh storage root yield, reflecting the breeding value of these parents. Relatively high narrow sense heritability (h2) was obtained for β-carotene content (79.8%) and HI (48.6%). However, the h2 estimates of storage root DMC, SPVD, and fresh storage root yield were relatively low at 19.0%, 14.9%, and 20.4%, respectively. Crosses with high β-carotene content such as Ukerewe × Resisto, Resisto × Ogansagan, Eumula × Pipi, and NASPOT 1 × Temesgen exhibited high storage root DMC. These families also had medium-to-high mean fresh storage root yield. Therefore, progenies derived from these families are good candidates to develop improved OFSP varieties with high storage root DMC.


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