Uticaj Oprašivača na Biološke Osobine i Kvalitet Ploda Jabuke (Malus Domestica Borkh.)

Abstract

Istraživanjima u okviru ove doktorske disertacije ispitan je uticaj oprašivača na biološke osobine novointrodukovanih sorti jabuke: ‘Gala Must’, ‘Red Elstar’, ‘Rajka’ i ‘Topaz’ u agroekološkim uslovima Čačka. Proučavane su fiziološke osobine (fenofaza cvetanja, fenofaza oprašivanja i oplođenja, i fenofaza zrenja plodova), pomološke osobine (morfometrijske, hemijske i organoleptičke) i produktivne osobine (prinos po stablu i prinos po jedinici površine) navedenih sorti jabuke u kombinacijama međusobnih oprašivanja, kao i u varijanti slobodnog oprašivanja.

Fenofaza cvetanja i zrenja ploda je utvrđena standardnim metodama za ovu vrstu istraživanja. Ispitana je klijavost polena in vitroproučavanih sorti jabuke, kvantitativna efikasnost rasta polenovih cevčica (broj polenovih cevčica i njihov rast u pojedinim delovima stubića) metodom fluorescentne mikropskopije, kao i inicijalno i finalno zametanje plodova u zavisnosti od oprašivača. Morfometrijski parametri ploda (masa, visina, širina, indeks oblika, dužina peteljke i broj semenki u plodu), kao i hemijske osobine ploda (sadržaj ukupnih i rastvorljivih suvih materija, sadržaj ukupnih, invertnih šećera i saharoze, sadržaj ukupnih kiselina, pH vrednost soka ploda i sadržaj ukupnih mineralnih materija) utvrđeni su standardnim laboratorijskim metodama. Organoleptička ocena ploda (intenzitet dopunske boje pokožice, atraktivnost, ukus, aroma i konzistencija ploda) utvrđena je poentiranjem u skladu sa UPOV metodologijom navedenom u uputstvima za priznavanje i zaštitu sorti jabuke. Prinos ispitivanih sorti jabuke u zavisnosti od oprašivača utvrđen je računskim putem.

Sorta ‘Rajka’ pripada grupi srednjeranocvetnih, dok ostale sorte pripadaju grupi srednjepoznocvetnih sorti jabuke. Po vremenu zrenja sorte ‘Gala Must’ i ‘Red Elstar’ su jesenje, dok su sorte ‘Rajka’ i ‘Topaz’ zimske sorte jabuke. Kvantitativni parametri rasta polenovih cevčica u stubiću tučka ispitivanih sorti jabuke ukazuju na postojanje uticaja genotipa oprašivača, ali i njegovog zahteva u pogledu temperaturnih uslova. Kod svih kompatibilnih kombinacija ukrštanja šest dana nakon oprašivanja konstatovan je prodor polenovih cevčica u bazu stubića, izuzev kod varijante slobodnog oprašivanja sorte ‘Gala Must’, kao i u kombinaciji ‘Rajka’  ‘Gala Must’ u drugoj godini ispitivanja. Kod svih kombinacija oprašivanja utvrđen je visok procenat inicijalnog i finalnog zametanja plodova, uslovljen sortom oprašivačem i godinom ispitivanja.

Alternate abstract:

The influence of pollenisers on biological properties of the newly introduced apple cultivars ‘Gala Must’, ‘Red Elstar’, ‘Rajka’ and ‘Topaz’ grown in the region of Čačak were investigated within the scope of this doctoral dissertation. Among the crosspollination, as well as in an open pollination variants within the cultivars abovementioned, the following parameters were studied: physiological properties (flowering phenophase, pollination and fertilisation phenophase, and fruit ripening phenophase), pomological properties (morphometric, chemical and organoleptic) and production properties (yield per tree and yield per unit land area).

Flowering and fruit ripening phenophases were determined by using standard method. In vitropollen germination rate of the studied apple cultivars, as well as quantitative efficacy of pollen tubes growth (number of pollen tubes and characteristics of their growth in particular regions of the style) monitored by fluorescent microscopy and the initial and final fruit set depending on polleniser, were analysed. Morphometric parameters of the fruit (weight, length, width, shape index, stalk length and seed number) along with chemical properties of the fruit (total and soluble solids content, total, inverted sugars and sucrose content, total acids, fruit juice pH value and total minerals content) were determined by standard methods. Organoleptic assessment of the fruit (over colour intensity, attractiveness, flavour, aroma and fruit consistency) involved grading based on UPOV instructions stated in cultivar release and apple cultivars protection procedures. Yield of the studied apple cultivars as influenced by polleniser was calculated manually.

‘Rajka’ belongs to the group of mid-early flowering cultivars, whereas the other assessed cultivars are classified as mid-late flowering. As regards harvest maturity, ‘Gala Must’ and ‘Red Elstar’ belong to the group of autumn cultivars, while ‘Rajka’ and ‘Topaz’ are winter cultivars. Quantitative parameters of pollen tubes growth in the style suggest not only the influence of polleniser genotype, but also point to temperature dependence of this influence. Six days after pollination pollen tubes were observed to penetrate the style base in all compatible pollination variants, except the cross ‘Rajka’ ‘Gala Must’ and open pollinated ‘Gala Must’ in the second year of the study. High initial and final fruit set were recorded in all pollination variants, and depended on polleniser and year of study.