Variation in growth, nutrition and phytochemicals of sequentially harvested shoots and fruits, and genetic studies of Lagenaria siceraria landraces in South Africa
| dc.contributor.advisor | Ntuli, N.R. Mavengahama, S. and Sibiya, J. | |
| dc.contributor.author | Buthelezi, Lungelo Given | |
| dc.date.accessioned | 2024-07-04T07:13:41Z | |
| dc.date.available | 2024-07-04T07:13:41Z | |
| dc.date.issued | 2024 | |
| dc.description | A Thesis submitted to the Faculty of Science, Agriculture and Engineering in fulfilment of the requirements for the Degree of Doctor of Philosophy in Botany in the Department of Botany at the University of Zululand, South Africa [2024]. | en |
| dc.description.abstract | Lagenaria siceraria (Molina) Standley, a member of the Cucurbitaceae family, is valued for its many uses, serving as a crucial food source with edible plant parts such as leaves, shoots, fruit pulp, and seeds. However, studies on L. siceraria regarding the relationship between shoot, peduncle and fruit traits during growth; nutritional and phytochemical composition of sequentially harvested shoots and fruits; as well as genetic diversity among landraces using single nucleotide polymorphism (SNP) markers, are limited. These studies are crucial for enhancing plant physiological understanding, optimizing crop yields, improving nutritional value, and preserving genetic diversity in L. siceraria. Therefore, the objectives of this study were to correlate shoot, peduncle, and fruits’ traits during growth; compare the nutritional composition of shoots and fruits, and phytochemical profile of fruits harvested at different maturity stages; and assess the genetic variability using SNP markers in L. siceraria landraces sourced from northern KwaZulu-Natal and Limpopo, South Africa. Multivariate analyses were conducted along with the estimations of heritability. Harvested shoot, peduncle, and fruit traits showed significant variation (p < 0.05) within each growth period and at different growth stages. Peduncles of all landraces became shorter and thicker when fruits were elongating and widening, from 0–5 days after anthesis (DAA). Positive correlations were notable among all shoot traits (shoot length, shoot width, shoot fresh mass, shoot dry mass, and shoot moisture content), and peduncle width correlating with fruit length and width. The first three principal components explained 85% of the total variability. Clustering identified three main groups, with singlets for landraces KRI and NSRC. Landraces were clustered according to peduncle and fruit sizes, as well as availability of harvestable shoots. High heritability estimates were recorded for peduncle length (55.2%) and shoot width (60.2%). Differences in nutrient attributes were significant within and among landraces where shoots and fruits were harvested at various growth stages. Nutritional traits correlated either positively or negatively with each other based on their translocation modes and similar chemical properties. The first five principal components explained 90.218% and 89.918% total variability in shoots and fruits, respectively. Micronutrients Ca, Mg, K, P, and N in shoots and macronutrients Fe, Zn, Cu, and Al in fruits, were the primary contributors of variability. Shoot nutrient content associated landraces into three major clusters, based on landraces with superior and inferior levels of specific nutrients at different growth stages, as well as those with distinctive nutrient profiles. Fruit nutrient status also grouped landraces into two major clusters, reflecting variations in nutrient content at different growth stages. Phytochemical analysis identified five isoprenoids in fruits harvested at 7 DAA across all landraces, namely 1-Dodecene, 2,3-Dimethyldodecane, E-15-Heptadecenal, Eicosane, and Tridecane, 6-propyl. Lighter metabolites in molecular mass displayed shorter retention rates (9.08-16.29 min) with lower relative peak areas (1.09-6.97%), while heavier compounds exhibited longer retention rates (13.42-18.00 mins) with higher relative peak areas (2.25-11.41%). Landraces were grouped into five clusters based on fruit and seed attributes and significant isoprenoid units. Terpenoids were the predominant phytochemicals commonly identified among landraces’ fruits at different stages of growth, where 1-Dodecene; Decane,3,7-dimethyl-; 1-Octadecane; 1-Pentadecene; E-14-Hexadecenal; E-15-Heptadecenal; Eicosane; Tetradecane, 4-methyl; and Tridecane, 6-propyl-, were the highest contributors to variation. Correlation in phytochemicals was predominantly based on their availability at different fruit growth stages. Three distinct clusters grouped landraces according to the unique presence of phytochemicals at different stages of growth, as well as landraces with similar fruit traits and phytochemical availability at different growth stages. Genetic variation at a single nucleotide base was identified among studied landraces, where the sequencing of 16 landraces revealed variations in the target genes ACS27 and CmFIS8. Molecular variance analysis and phylogenetic tree construction indicated variations among landraces. Sequenced landraces showed an average of 1.75 alleles, effective alleles at 0.419, Shannon’s information index at 0.403, expected heterozygosity at 0.265, gene flow at 6.80, and genetic differentiation at 0.082. Sequence variations were observed, and landraces were clustered based on genetic differences. Analysis of Molecular Variance (AMOVA) indicated 100% variation among landraces of different origins. | en |
| dc.description.abstract | OKUHUNYUSHWE NGOLIMI LWESIZULU OKUFINGQIWE ISelwa ilungu lomndeni wezintanga elaziswa kakhulu ngenxa yemisebenzi yalo eminingi, njengoba lisebenza njengomthombo wokudla obalulekile ngenxa yamalunga esitshalo amaningi adliwayo okufaka kuwo namaqabunga, imiliba, ingaphakathi lezithelo, kanye nembewu. Noma kunjalo, ziyashoda izifundo (ucwaningo) ngamaSelwa mayelana nobudlelwane obubakhona phakathi kwemiliba, izingono kanye nezithelo ngesikhathi sokukhula; ukwakheka komsoco kanye nezivikelamzimba zemiliba kanye nezithelo ngesikhathi zivunwa ngokulandelana; kanye nokuhlukahluka kwamaSelwa kusetshenziswa indela yolibofuzo olubuka umehluko kwisakhi ngasodwana. Ngakho-ke, lolucwaningo lusebenzise amaSelwa asenyakatho neKwaZulu-Natali kanye naseLimpopo eNingizimu Afrika, ngezinhloso zokuhlobanisa izimpawu ezenzekayo nezibonakalayo phakathi kwemiliba, izingono, kanye nezithelo ngesikhathi zikhula; ukuqhathanisa ukwakheka komsoco (kwezakhamizimba) kwimiliba nezithelo, kanye nokwakheka kwezivikelamzimba yezithelo uma zivunwa ngezigaba ezahlukene zokukhula; kubuye kuhlolwe ukuhlukahluka kwamaSelwa kusetshenziswa indela yolibofuzo olubuka umehluko wesakhi ngasodwana. Ukuhlaziywa kwemiphumela kwakubuka ukwehluka, ukuhlobana, ukuhlaziywa kwezingxenye eziyizinhloko (ezenza umehluko osobala), ukuhlaziya ngamaqoqo, nezilinganiso zofuzo. Kwatholakala ukwehlukahlukana okusobala (p < 0.05) kwimiliba, izingono nezithelo zeSelwa elilodwa ngezikhathi ezehlukene zokukhula, kanye namaSelwa ahlukene ehlolwa esigabeni esisodwa sokukhula. Kuzozonke izinhlobo zamaSelwa, uma amaSelwa ekhula kusukela osukwini lokuqala kuya kolwesihlanu emva kokwamukela inqakazo, izingono ziba mfishane zande ngomzimba ngesikhathi izithelo seluleka zibazinkulu ngesidumbu, Ukuhlobana okuhle kwaphawuleka phakathi kwalezizingxenye zamaSelwa nezikhathi ezihlukene zokukhula; lokhu kubonakala kwiSelwa ngalinye nalapho liqhathaniswa namanye. Izingxenye ezintathu zokuqala eziyinhloko zichaze okungamashumi ayisishagalombili nanhlanu ekhulwini (85%) kwengqikithi yokuhlukahluka. Ukuhlanganisa ngokuhlobana kuhlonze amaqoqo amathathu amakhulu amaSelwa ahlobene, bese kuthi izonhlobo ezibizwa ngo-KRI kanye no-NSRC zahlala ngazodwana. Lokhukuqoqana kwamaSelwa kwakwencike kakhulu kubunjalo bengono nezithelo kanye nokubakhona (ukutholakala) kwemiliba engavuneka (engakheka). Izilinganiso eziphezulu zokudluliselana ngofuzo zatholakala ubudeni bezingono (55.2%) kanye nobubanzi bemiliba (60.2%). Ubungako kanye nezinhlobo zezakhamizimba zemiliba nezezithelo zazehlukile kakhulu kwiSelwa ngalinye ngezikhathi ezehlukene zokukhula, kanye naphakathi kwamaSelwa ahlukene uma kuhlolwa esigabeni esisodwa. Izinhlobo ezehlukene zezakhamizimba zazihlobana kahle noma kabi, kususelwa ngokwezindlella ezihamba ngayo esitshalweni kanye kokwakheka kwazo. Izingxenye ezinhlanu zokuqala eziyizinhloko zichaze u-90.218% kanye no-89.918% wokuhlukahluka okuphelele kwemiliba nezithelo, ngokulandelana. Izakhamizimba ezingumthamo omkhulu okuyi-Ca, Mg, K, P, no-N kwimiliba, kanye nalezo ezingumthamo omncane okuyi-Fe, Zn, Cu, ne-Al ezithelweni, yizona ezibambe iqhaza ngokuyizinhloko ekuhlukeni. Izakhamizimba ezitholakala emilibeni zihlukanise amaSelwa ngokwamaqoqo amathathu amakhulu, kususelwa ebuningini noma ebincaneni bomthamo wezakhamizimba ezithize, kanye nezakhamizimba ezihlukile nje ngokwazo. Isimo sezakhamizimba wezithelo siphinde senza amaqoqo amabili amakhulu amaSelwa, okubonisa ukuhlukahluka ngokwezakhamizimba ezigabeni zokukhula ezihlukene. Ukuhlaziywa kwezivikelamizimba ezithelweni zazozonke izinhlobo zamaSelwa emva kwezinsuku eziyisikhombisa zamukele inqakazo, kwahlonza ama-isoprenoid amahlanu, okuyi-1-Dodecene, 2,3-Dimethyldodecane, E-15-Heptadecenal, Eicosane, ne-Tridecane, 6-propyl ukuthi atholakala kuwo wonke amaSelwa. Lezozivikelamizimba ezinesisindo esilula zahlonzwa emva kwesikhathi esincane (imizuzu esukela ku 9.08–16.29) futhi emazingeni aphansi okubonakala komthamo (ubungako kwikhulu busukela ku 1.09–6.97), kuyilapho izinhlanganisela ezisindayo zabonakala emva kwesikhathi eside (imizuzu esukela ku 13.42–18.00) futhi zingumthamo ophakeme (ubungako kwikhulu busukela ku 2.25–11.41). AmaSelwa aba ngamaqoqo amahlanu kususelwa kwizimpawu zezithelo nembewu kanye nobukhulu bezinhlobo bezivikelamizimba. Izivikelamizimba ezikumndeni wama-Terpenoids yizona ezazitholakala kuzozonke izithelo zezinhlobo ezehlukene zamaSelwa ezigabeni ezahlukene zokukhula, lapho i-1-Dodecene; Decane,3,7-dimethyl-; 1-Octadecane; 1-Pentadecene; E-14-Hexadecenal; E-15-Heptadecenal; Eicosane; Tetradecane,4-methyl; kanye ne-Tridecane, 6-propyl-, babe negalelo eliphakeme kakhulu ekwehlukeni kwezinhlobo zamaSelwa ezigabeni ezehlukene zokukhula. Ukuhlobana kwezivikelamizimba kwakwencike kakhulu ekutholakaleni kwazo ezigabeni ezihlukene zokukhula kwezithelo. Amaqoqo amathathu ahlukene amaSelwa avela kususelwa kwizakhamzimba ezikhethekile futhi ezitholakala ngesikhathi esehlukile sokukhula, amaSelwa abukeka ehlobene ngaphandle, kanye nezakhamizimba ezifanayo kodwa ezivela ngezikhathi zokukhula ezehlukeneyo. Ukwehluka kolibofuzo kusisekelo sesakhi esisodwa kwabonakala phakathi kwamaSelwa, lapho ukubala ngokulandelana kwezakhi ngazinye kumaSelwa ayishumi nesithupha kwaveza ukwahlukana okuboniswa iziphathifuzo okuyi-ACS27 ne-CmFIS8. Ukuhlaziywa kwezakhi zolibofuzo kanye nokuhlobana ngofuzo, kwakhombisa umehluko phakathi kwezinhlobo zamaSelwa. Ukubala ngokulandelana kwezakhi zolibofuzo phakathi kwamaSelwa kwaveza izilinganiso ezingu-1.75 zolibofuzo olukwaziyo ukushintshana phakathi kwembewu yabazali, esingu-0.49 solubofuzo olulindeleke ukuthi lushintshane phakathi kwabazali kuya enganeni, i-Shannon’s information index engu-0.403, kanye nokuhlukana okusobala okulindelekile kulibofuzo okungu-0.265, ukugeleza kweziphathifuzo ngokwezizukulwane okungu-6.80, kanye nokuhlukaniswa kolibofuzo okungu-0.082. Ukubala ngokulandelana kwezisekelo zezakhi ngazodwa zolibofuzo kwakhombisa ukwehlukana phakathi kwamaSelwa, kanti ukwehlukana kolibofuzo kwaba yimbangela yamaqoqo phakathi kwamaSelwa. Ukuhlukahluka kokulandelana kwezakhi zeziphathifuzo kwabonakala, kanti nezinhlobo zamaSelwa zenza amaqoqo ngokokuhlukana kolibofuzo lwazo. Izinhlobo zamaSelwa ezingezokudabuka ezindaweni ezehlukene zakhombisa ukungabi nabo ubuhlobo uma kuhlaziywa ngendlela yokubuka ukwahlukahlukana kwezakhi zolibofuzo. | zu |
| dc.identifier.uri | https://uzspace.unizulu.ac.za/handle/10530/2526 | |
| dc.language.iso | en | |
| dc.publisher | University of Zululand | en |
| dc.title | Variation in growth, nutrition and phytochemicals of sequentially harvested shoots and fruits, and genetic studies of Lagenaria siceraria landraces in South Africa | en |
| dc.title.alternative | Nutrition and phytochemicals | en |
| dc.type | Thesis | en |