Genetic analyses and association mapping were performed on a winter wheat core collection of 96 accessions sampled from a variety of geographic origins. Twenty-four agronomic traits were evaluated over 3 years under fully irrigated, rainfed and drought treatments. Grain yield was the most sensitive trait to water deficit and was highly correlated with above-ground biomass per plant and number of kernels per m2. The germplasm was structured into four subpopulations. The association of 46 SSR loci distributed throughout the wheat genome with yield and agronomic traits was analyzed using a general linear model, where subpopulation information was used to control false-positive or spurious marker-trait associations (MTAs). A total of 26, 21 and 29 significant (P < 0.001) MTAs were identified in irrigated, rainfed and drought treatments, respectively. The marker effects ranged from 14.0 to 50.8%. Combined across all treatments, 34 significant (P < 0.001) MTAs were identified with nine markers, and R2 ranged from 14.5 to 50.2%. Marker psp3200 (6DS) and particularly gwm484 (2DS) were associated with many significant MTAs in each treatment and explained the greatest proportion of phenotypic variation. Although we were not able to recognize any marker related to grain yield under drought stress, a number of MTAs associated with developmental and agronomic traits highly correlated with grain yield under drought were identified.

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When water stress develops post-anthesis, wheat (Triticum aestivum L.) plants have to rely increasingly on remobilization of previously stored assimilates to maintain grain filling. In two-year field trials, we studied more than 20 agronomic and developmental traits in 61 wheat genotypes (27 F4:5 families, 17 parents used for the crosses and 17 standards), comparing plants that were defoliated (DP) by cutting off all leaf blades 10 days after anthesis with intact control plants (CP). Estimated contributions of stem and sheath assimilate reserves to grain weight/spike were from 10-54% and from 24-84% in CP and DP plants, respectively. Stem-related traits were among key traits determining stem reserve contribution (SRC). The most important genetic variables in differentiating genotypes for stress tolerance were biomass/stem, stem reserves mobilization efficiency and grain filling rate (GFR). Balance among traits related to yield maintenance in DP were more important than their high values. In general F4:5 families (FAM), that had been crossed to combine typical breeding traits such as biomass and yield components, showed better tolerance under moderate stress than standards and parents.

The research on the effect of ecological conditions and cultivars on the yield components of potatoes was conducted in Badovinci (Western Serbia) during the period 2008-2009. The following potato cultivars were included in the experiment: early ('Cleopatra', 'Anushka' and 'Presto'), medium early ('Kuroda', 'Omega' and 'Dita'), and medium late ('Desiree', 'Roko' and 'Jelly'). The four-replicate field trials were set up using the standard methodology according to the random block design. 1 8 T The research results suggest that genotype (G) and ecological conditions (E) significantly affect all yield components of potatoes. In both years, the highest yield was recorded1 8 T in1 8 T the medium late variety 'Desiree'1 8 T 1 8 T (1 8 T 28.30 t ha‫,)¹-‬ followed by the early variety 'Anushka' 1 8 T (1 8 T 26.60 t ha‫,)¹-‬ 1 8 T while the lowest1 8 T 1 8 T yield1 8 T was 1 8 T recorded1 8 T 1 8 T in the medium early variety 'Omega' (1 8 T 13.35 t ha‫.)¹-‬ The 1 8 T results obtained show that1 8 T 1 8 T the1 8 T 1 8 T highest yields1 8 T in Western Serbia were 1 8 T recorded in early varieties1 8 T 1 8 T ('Cleopatra'1 8 T , 'Anushka' 1 8 T and1 8 T '1 8 T Presto'1 8 T) and 1 8 T medium1 8 T 1 8 T late varieties1 8 T 1 8 T ('1 8 T Desiree'), which exhibited considerable1 8 T resistance to high1 8 T 1 8 T air temperatures1 8 T and 1 8 T drought stress1 8 T. REZIME Komponente prinosa devet sorti krompira ispitivane su tokom 2008. i 2009. godine na lokaciji zapadne Srbije u selu Badovinci (75 m nadmorska visina, 44˚8044˚80' 05"N, 19˚3519˚35' 39"E). Za istraživanje korišćene su sledeće sorte krompira: rane (Cleopatra, Anushka i Presto), srednje rane (Kuroda, Omega i Dita) i srednje kasne (Desiree, Roko i Jelly). Sadnja je izvedena u prvoj dekadi aprila. Međuredno rastojanje bilo je 0,70 m a između biljaka u redu 0,30 m. Primenjena je standardna tehnologija gajenja krompira. Broj primarnih nadzemnih izdanaka određen je 65 dana posle sadnje krtola. Vađenje krompira izvršeno je početkom septembra kada je izvršeno i utvrđivanje broja krtola po biljci i ukupan prinos. 1 8 T Dobijeni rezultati ukazuju da su sorta (G) i agroekološki uslovi (E) značajno utiču na sve komponente prinosa krompira. U obe godine najveći ukupan prinos krtola zabeležen je kod srednje kasne sorte Desiree1 8 T 1 8 T (1 8 T 28,30 t ha‫,)¹-‬ zatim kod rane sorte Anushka 1 8 T (1 8 T 26,60 t ha‫,)¹-‬ dok je najniži prinos krtola utvrđen kod srednje rane sorte 1 8 T Omega (1 8 T 13,35 t ha‫.)¹-‬ Na osnovu rezultata dvogodišnjih istraživanja uticaja sorte i agroekoloških uslova na komponente prinosa u zapadnoj Srbiji, možemo izvesti sledeće zaključke:-Sorta i uslovi sredine pojedinačno i u interakciji značajno utiču na komponente prinosa1 8 T ; Za dobijanje visokih prinosa krtola u uslovima zapadne Srbije možemo preporučiti rane sorte (1 8 T Cleopatra, Anushka 1 8 T i1 8 T P1 8 T resto1 8 T), posebno u godinama sa malom količinom padavina, kao i srednje kasnu sortu 1 8 T (1 8 T Desiree), koja je pokazala dobru tolerantnost prema visokim temperaturama vazduha i suši.